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1
|
|
|
|
QA36
.W4
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Variational methods for eigenvalue approximation
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Philadelphia, [ United States ] : Society for Industrial and Applied Mathematics , 1974
|
Weinberger, Hans F
|
|
10369
|
|
2
|
|
|
|
QA372
.P7
|
Maximum principles in differential equations
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New Jersey, [ United States ] : Prentice Hall , 1967
|
Protter, Murray H
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47219
|