preamble.sty~

\ProvidesPackage{preamble}

\usepackage{subfiles}
\usepackage[style=ieee]{biblatex}
\addbibresource{references.bib}

\AtBeginDocument{%
}

\AtEndDocument{%
    \printbibliography
}

\newcommand{\onlyinsubfile}[1]{#1}
\newcommand{\notinsubfile}[1]{}