Periodic solutions of a third order nonlinear differential equation
1972 ◽
Vol 92
(1)
◽
pp. 193-198
◽
2010 ◽
Vol 51
(3)
◽
pp. 033518
◽
2009 ◽
Vol 2009
◽
pp. 1-14
◽
2010 ◽
Vol 216
(10)
◽
pp. 3044-3049
◽
2008 ◽
Vol 4
(2)
◽
pp. 88-93
◽