To cite the \emph{ probit.bayes } Zelig model:
 \begin{verse}
 Ben Goodrich and Ying Lu. 2007. "probit.bayes: Bayesian Probit Regression for Dichotomous Dependent Variables" in Kosuke Imai, Gary King, and Olivia Lau, "Zelig: Everyone's Statistical Software,"\url{http://gking.harvard.edu/zelig} 
\end{verse}