TY  - BOOK
AU  - Bogoliubov N N
AU  -  Mitropolsky Y A
TI  - Asymptotic methods in the theory of non-linear oscillations
T2  - International monographs on advanced mathematics and physics
U1  - B7:5, K1-;1 
PY  - 1961///
KW  - Mechanics
ER  -