LaTeX.org

can't believe...
changed the name of the file from
Books and notes.bib
to
Books.bib

it all works now!!!
Should be no space in the name of the bib-file, why??

Hello,
thank you for your answer.

Please have a look to the bib file:

%
%Linear Elastic Fracture Mechanics
@book{fischer2007introduction,
title={Introduction to contact mechanics},
author={Fischer-Cripps, Anthony C},
volume={101},
year={2007},
publisher={Springer}
}
%
%Fracture mechanics ...

Hello everyone,
compiling bibtex file in TexMaker as:

\documentclass[11pt]{article}
\usepackage{apacite}
\usepackage[margin=1in]{geometry}
\usepackage{natbib}

\title{Literature Review}
\author{A. Francese}
\date{\today}

\begin{document}
\maketitle

Books and Notes, \cite ...