[biblio] Multiple author Error

[AKI]

I am getting error with my master thesis final draft !

I am using Ucalgary thesis class ! (Attached)

Problem comes when i use multiauthor like

 @article{Schonewille02,

year = {2009},

author = {Schonewille, M and Klaedtke, A and Vigner, A and Brittan, J and
Martin, T},

journal = {First Break},

volume = {27},

pages = {85-92},

title = {Seismic data regularization with the anti-alias anti-leakage
Fourier transform},

}

Below is how i used in my tex file

  Parametric analysis based reconstruction methods are based on the
\textit{a priori} information from the seismic data alone
\cite{Naghizadeh15}. Most parametric reconstruction methods are based on
Fourier transformation from one domain to another \cite{Naghizadeh11,
Naghizadeh12, Naghizadeh14}. In the last few years excellent research is
been done in this area \cite{Liu02, Schonewille02}.The Prior assumption is
either based on the stationarity of the process or based on the fact that
most of the power in the power spectrum is concentrated on the lower
frequencies, analysis based on this fact known as bandlimitness
\cite{Naghizadeh16}. Bandlimitness enforces only the use of certain set of
frequencies \cite{Feichtinger01}. These algorithms perform efficiently even
in situations where bandlimited assumption is not satisfied exactly
\cite{Trad03}.



Headers for my main thesis file are

\documentclass{ucalgthes} % Remove [includeprompt] to process all

%%% These are the packages I usually use. You can always add or take away
packages to make your life easier

\usepackage{graphicx}

\usepackage{amsmath}

\usepackage{url}

\usepackage{subfig}


 \bibliography{references} %%% Use the name of your bib file

\bibliographystyle{crewes}

using natbib package in starting giving me error .attach is the log file

Thanks

kk
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://tug.org/pipermail/biblio/attachments/20110404/0a2f5cda/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: latex_UofCThesis_linux (1).tgz
Type: application/x-gzip
Size: 28977 bytes
Desc: not available
URL: <http://tug.org/pipermail/biblio/attachments/20110404/0a2f5cda/attachment-0001.tgz>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: output.pdf
Type: application/pdf
Size: 19178 bytes
Desc: not available
URL: <http://tug.org/pipermail/biblio/attachments/20110404/0a2f5cda/attachment-0001.pdf>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: MyThesis_main.log
Type: text/x-log
Size: 21675 bytes
Desc: not available
URL: <http://tug.org/pipermail/biblio/attachments/20110404/0a2f5cda/attachment-0001.bin>