000
00307nam a2200109 4500
008
160616s 000 0
245
_a
Exterior differential systems and the calculus of variations
100
_a
Griffiths, P.A
440
_a
Progress in mathematics ; 00025
942
_c
BK
_2
BK1357
080
_a
51 PM
999
_c
1357
_d
1357