@article{10_21136_AM_1988_104300,
     author = {T\r{u}ma, Miroslav},
     title = {A note on direct methods for approximations of sparse {Hessian} matrices},
     journal = {Applications of Mathematics},
     pages = {171--176},
     publisher = {mathdoc},
     volume = {33},
     number = {3},
     year = {1988},
     doi = {10.21136/AM.1988.104300},
     mrnumber = {0944781},
     zbl = {0658.65058},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.21136/AM.1988.104300/}
}