BibTeX
@ARTICLE{
         Powell1979OtE,
       author = "Michael J. D. Powell and Philippe L. Toint",
       title = "On the Estimation of Sparse {H}essian Matrices",
       journal = "SIAM J. Numer. Anal.",
       pages = "1060--1074",
       key = "Powell1979OtE",
       referred = "[Hossain2001RtN], [More2001ADT].",
       year = "1979",
       volume = "16",
       ad_theotech = "Hessian, Sparsity"
}