000
00271nam a2200109Ia 4500
008
210212s9999||||xx |||||||||||||| ||und||
100
_a
Open university
245
0
_a
Finite Differences
260
_c
1971
_b
Open university press
_a
Bletchley
300
_a
61p.
942
_c
SU
999
_c
88033
_d
88033