\documentclass{article}
\usepackage[pagebackref]{hyperref}
\begin{document}
\cite{abc,def,ghi}

\begin{thebibliography}{9}
\bibitem{abc} The ABC book.

\backrefparscanfalse
\bibitem{def} The DEF book, \url{http://somewhere/%20xy}.
\backrefprint
\backrefparscantrue

\bibitem{ghi} The GHI book.

\end{thebibliography}
\end{document}