000
00253nam a2200109 4500
008
160616s 000 0
245
_a
Variational principles
100
_a
Moiseiwitsch, B.L
500
_a
Bobc k63
942
_c
BK
_2
BK2335
080
_a
53:51 MOI
999
_c
2335
_d
2335