Bibliography: latex error something's wrong--perhaps a missing item

Question

I got always the error "latex error something's wrong--perhaps a missing item" in the two first items of my bibliography. In the output, the first item is not taken and the second one has two reference as you can see on this screenshot:

This is a code snap of the bibliography:

\phantomsection              
\addcontentsline{toc}{chapter}{\bibname} 
\bibliographystyle{bib/bmc-mathphys}  
\begin{thebibliography}
\bibitem{b1} ..... 
\end{thebibliography}