@Article{xxx-01,
  author-1 =     "Nikola{\u\i} Nikolaevich Bogoljubov",
  author-2 =     "Nikola{\u{\i}} Nikolaevich Bogoljubov",
  author-3 =     "Nikola{\u{{\i}}} Nikolaevich Bogoljubov",
  author-4 =     "Nikola{\u{{}\i}} Nikolaevich Bogoljubov",
  author-5 =     "Nikola{\u{{}{}\i}} Nikolaevich Bogoljubov",
  author-6 =     "Nikola{\u{{}{}{}\i}} Nikolaevich Bogoljubov",
}

@Article{xxx-02,
  author-1 =     "Nikola{\u \i} Nikolaevich Bogoljubov",
  author-2 =     "Nikola{\u {\i}} Nikolaevich Bogoljubov",
  author-3 =     "Nikola{\u {{\i}}} Nikolaevich Bogoljubov",
  author-4 =     "Nikola{\u {{}\i}} Nikolaevich Bogoljubov",
  author-5 =     "Nikola{\u {{}{}\i}} Nikolaevich Bogoljubov",
  author-6 =     "Nikola{\u {{}{}{}\i}} Nikolaevich Bogoljubov",
}

@Article{xxx-03,
  author-1 =     "Nikola{\u \i } Nikolaevich Bogoljubov",
  author-2 =     "Nikola{\u {\i }} Nikolaevich Bogoljubov",
  author-3 =     "Nikola{\u {{\i }}} Nikolaevich Bogoljubov",
  author-4 =     "Nikola{\u {{}\i }} Nikolaevich Bogoljubov",
  author-5 =     "Nikola{\u {{}{}\i }} Nikolaevich Bogoljubov",
  author-6 =     "Nikola{\u {{}{}{}\i }} Nikolaevich Bogoljubov",
}

@Article{xxx-04,
    author-1  =          "Nikola{\u  \i  }  Nikolaevich  Bogoljubov",
    author-2  =          "Nikola{\u  {\i  }}  Nikolaevich  Bogoljubov",
    author-3  =          "Nikola{\u  {{\i  }}}  Nikolaevich  Bogoljubov",
    author-4  =          "Nikola{\u  {{}\i  }}  Nikolaevich  Bogoljubov",
    author-5  =          "Nikola{\u  {{}{}\i  }}  Nikolaevich  Bogoljubov",
    author-6  =          "Nikola{\u  {{}{}{}\i  }}  Nikolaevich  Bogoljubov",
}

@Article{xxx-05,
  author-1 =     "Nikola{\u{\i}} Nikolaevich Bogoljubov",
  author-2 =     "Nikola{\u{{\i}}} Nikolaevich Bogoljubov",
  author-3 =     "Nikola{\u{{{\i}}}} Nikolaevich Bogoljubov",
  author-4 =     "Nikola{\u{{}{\i}}} Nikolaevich Bogoljubov",
  author-5 =     "Nikola{\u{{}{}{\i}}} Nikolaevich Bogoljubov",
  author-6 =     "Nikola{\u{{}{}{}{\i}}} Nikolaevich Bogoljubov",
}

@Article{xxx-06,
  author-1 =     "Nikola{\u {\i}} Nikolaevich Bogoljubov",
  author-2 =     "Nikola{\u {{\i}}} Nikolaevich Bogoljubov",
  author-3 =     "Nikola{\u {{{\i}}}} Nikolaevich Bogoljubov",
  author-4 =     "Nikola{\u {{}{\i}}} Nikolaevich Bogoljubov",
  author-5 =     "Nikola{\u {{}{}{\i}}} Nikolaevich Bogoljubov",
  author-6 =     "Nikola{\u {{}{}{}{\i}}} Nikolaevich Bogoljubov",
}

@Article{xxx-07,
  author-1 =     "Nikola{\u {\i} } Nikolaevich Bogoljubov",
  author-2 =     "Nikola{\u {{\i} }} Nikolaevich Bogoljubov",
  author-3 =     "Nikola{\u {{{\i} }}} Nikolaevich Bogoljubov",
  author-4 =     "Nikola{\u {{}{\i} }} Nikolaevich Bogoljubov",
  author-5 =     "Nikola{\u {{}{}{\i} }} Nikolaevich Bogoljubov",
  author-6 =     "Nikola{\u {{}{}{}{\i} }} Nikolaevich Bogoljubov",
}

@Article{xxx-08,
    author-1  =          "Nikola{\u  {\i}  }  Nikolaevich  Bogoljubov",
    author-2  =          "Nikola{\u  {{\i}  }}  Nikolaevich  Bogoljubov",
    author-3  =          "Nikola{\u  {{{\i}  }}}  Nikolaevich  Bogoljubov",
    author-4  =          "Nikola{\u  {{}{\i}  }}  Nikolaevich  Bogoljubov",
    author-5  =          "Nikola{\u  {{}{}{\i}  }}  Nikolaevich  Bogoljubov",
    author-6  =          "Nikola{\u  {{}{}{}{\i}  }}  Nikolaevich  Bogoljubov",
}

@Article{xxx-09,
  title =        "Harmonic Radius and Concentration of Energy;
                 Hyperbolic Radius and {Liouville}'s Equations {$ \Delta
                 U = e^U $} and {$ \Delta U = U^{\frac {n + 2}{n - 2}}
                 $}",
}

@Article{xxx-10,
  booktitle =    "On $\frac {n + 2} {n - 2}$ and off{}loading",
  title =        "On $\frac {n + 2}{n - 2}$ and of{f}loading",
}

@Article{xxx-11,
  booktitle =    "On $\frac {n + 2} {n - 2}$ and off{{}}loading",
  title =        "On $\frac {n + 2}{n - 2}$ and of{{f}}loading",
}

@Article{xxx-12,
  booktitle =    "On $\frac {n + 2} {n - 2}$ and off{{{{{{{}}}}}}}loading",
  title =        "On $\frac {n + 2}{n - 2}$ and of{{{{{{{f}}}}}}}loading",
}

@Article{xxx-13,
  title =        "Math $_2{F}_2(\ldots)$"
}

@Article{xxx-14,
  title =        "The Asymptotic Expansion of a Hypergeometric Function
                 $_2{F}_2 (1, \alpha; \rho_1, \rho_2; z)$",
}

@Article{xxx-15,
  title =        "Multiple-pathways of carbon dioxide binding by a
                 {Lewis} acid {[B(C$_6$F$_5$)$_3$]} and a {Lewis} base
                 {[P(tBu)$_3$]}: the energy landscape perspective",
}

@Article{xxx-16,
  title =        "$_2{F}$"
}

@Article{xxx-17,
  title =        "$_2F$"
}

@Article{xxx-18,
  title =        "${}_2F$"
}

@Article{xxx-19,
  title =        "$_2{F}$"
}

@Article{xxx-20,
  title = "{Lewis} acid {[B(C$_6$F$_5$)$_3$]} and a {Lewis} base {[P(tBu)$_3$]}",
}

@Article{xxx-21,
 title = "($x$)",
 title = "( $x$ )",
 title = "[$x$]",
 title = "[ $x$ ]",
 title = "{$x$}",
 title = "{ $x$ }",
 title = "<$x$>",
 title = "< $x$ >",
 title = "$x$word",
 title = "$x$ value",
 title = "$x$-valued",
}

@Article{xxx-22,
  note =         "Cited in {{\AA}ke Bj{\"o}rck's} bibliography.",
  note =         "Cited in {\AA}ke Bj{\"o}rck's bibliography.",
  note =         "Cited in \AA ke Bj{\"o}rck's bibliography.",
}

@Article{xxx-23,
  title =        "Mixed mortar element method for {$P_1^{NC-}P_0$}
                 element and its multigrid for {Stokes} problem",
}

@Article{xxx-24,
 title = "Universidad pontificia de Santo Tom\'as",
 title = "{Universidad pontificia de Santo Tom\'as}",
}

@Article{xxx-25,
 title = "Le{\c {c}}ons",
 title = "Le{\c{c}}ons",
}

@Article{xxx-26,
 title = "On a Conjecture by {Erd\H os--Straus}",
 title = "On a Conjecture by {Erd{\H {o}}s--Straus}",
 title = "On a Conjecture by {Erd{\H{o}}s--Straus}",
}

@Article{xxx-27,
 title = "Review of {\em Programmeringsspr{\aa}k\/}",
 title = "Review of {\em Programmeringsspr\aa k\/}",
}

@Article{xxx-28,
 title = "Beltr{\'a}n Mar{\'\i}",
 title = "Beltr\'an Mar\'\i",
}

@Article{xxx-29,
 title = "{Georges Lema{\^\i}tre's} {\em annus mirabilis}",
 title = "{Georges Lema\^\itre's} {\em annus mirabilis}",
}

@Article{xxx-30,
 title = "Lema\^\itre",
 title = "Doro\u \j",
 title = "Doro\d k",
 title = "Bo\^\alpha",
 title = "Bo\^\beta",
}

@Article{xxx-31,
  editor = "Behram Kur\c suno\u glu and Eugene Paul Wigner",
  editor = "Behram Kur{\c{s}}uno{\u{g}}lu and Eugene Paul Wigner",
}

@Article{xxx-32,
    title = "{ECMA-236}: 3,81\,mm Wide Magnetic Tape Cartridge",
    title = "{ECMA-236}: 3,81,mm Wide Magnetic Tape Cartridge",
    title = "{ECMA-236}: 3,81, mm Wide Magnetic Tape Cartridge",
}

@Article{xxx-33,
    title = "The applicative part of APL\@. Sequences",
    title = "The applicative part of APL\@ . Sequences",
}

@Article{xxx-34,
  booktitle = "Semi\-nu\-mer\-i\-cal Algorithms",
  title = "The {Experium\TM} {Knowledge Resource System}",
  remark = "From \cite {Logan:1978:FDP}: ``Benford's paper was \ldots{}.''",
}

@Article{xxx-35,
 booktitle = "Below 3,000,000,000",
 title = "Below $3,000,000,000$",
 note = "Below $3\,000\,000\,000$",
}

@Article{xxx-36,
 title = "The $\alpha { and } \beta$ study",
}

@Article{xxx-37,
    title = "For $|x| >= 17$",
}

@Article{xxx-38,
    title = "For $|x| <= 17$",
}

@Article{xxx-39,
    title = "For $|x| := 17$",
}

@Article{xxx-40,
  title = "Applications (K\=oriyama, 1988)",
  title = "Applications (K\={o}riyama, 1988)",
  title = "Applications (K{\=o}riyama, 1988)",
}

@Article{xxx-41,
    title = "For $x > log(y)$", 
    title = "For $x > \log(y)$", 
}
