BibTeX not working with \input or \include [closed]

Question

I need some help with BibTeX. I use a seperate *.bib file which is working perfectly, but when the commands \input or \include are used to input text from another *.tex file the application tells me there are suddenly undefined resources. What is happening. I have tried running BibTeX on the aux-file created by the \include command.

\documentclass[a4paper,norsk, twoside,11pt, titlepage]{article}
\usepackage[utf8]{inputenc}
\usepackage{graphicx}
\usepackage{apacite}
\usepackage{varioref}
\usepackage{babel,textcomp}
\usepackage{microtype}
\usepackage{multirow}
\usepackage{array}
\usepackage{footnote}
\usepackage{placeins}
\usepackage{etoolbox}
\usepackage{enumerate}
\usepackage{lipsum}

\title{title}
\author{A}

\begin{document}

\cite{bibentry}

%\include{file}
%\input{file(.tex)}

\newpage
\bibliographystyle{apacite}
\bibliography{bibl}

 \end{document}