@article{ZVMMF_1971_11_6_a1,
     author = {N. Joachim Lehmann},
     title = {Hilfsmittel zur optimalen {Eigenwerteinschliessung.} {Ein} {Pendant} zum {Rayleigh{\textendash}Ritz{\textendash}Verfahren}},
     journal = {\v{Z}urnal vy\v{c}islitelʹnoj matematiki i matemati\v{c}eskoj fiziki},
     pages = {1374--1389},
     publisher = {mathdoc},
     volume = {11},
     number = {6},
     year = {1971},
     language = {de},
     url = {http://geodesic.mathdoc.fr/item/ZVMMF_1971_11_6_a1/}
}