\let\@fcitex\@citex    % hold the originals.
\let\@fcite\@cite      %


\def\@ffcite#1#2{\hbox{$^{{#1}}$}}
\def\@ffcitex[#1]#2{\if@filesw\immediate\write\@auxout{\string\citation{#2}}\fi
  \def\@citea{}\@cite{\@for\@citeb:=#2\do
    {\@citea\def\@citea{,\penalty\@m\ }\@ifundefined
       {b@\@citeb}{{\bf ?}\@warning
       {Citation `\@citeb' on page \thepage \space undefined}}%
 {\csname b@\@citeb\endcsname}}}{#1}}

\def\citefnote{\let\@cite\@ffcite\let\@citex\@ffcitex}
\def\citenorm{\let\@cite\@fcite\let\@citex\@fcitex}