BibTeX
@ARTICLE{
         Campbell1989ACM,
       AUTHOR = "Stephen L. Campbell",
       TITLE = "A Computational Method for General Higher Index Nonlinear Singular Systems of
         DIfferential Equations",
       JOURNAL = "IMACS Transactions on Scientific Computing",
       VOLUME = "1.2",
       YEAR = "1989",
       PAGES = "555--560",
       REFERRED = "[Campbell1996ADa]."
}