Lefschetz, S..
Contributions to the Theory of Nonlinear Oscillations / - 1st ed / - Princeton : Princeton University Press , 1987 - p.211 :
Nonlinear oscillations
B33 / J8
Contributions to the Theory of Nonlinear Oscillations / - 1st ed / - Princeton : Princeton University Press , 1987 - p.211 :
Nonlinear oscillations
B33 / J8