An oscillation theorem

Oscillation theorems for second order nonlinear forced differential equations

“…The oscillatory theory as a part of the qualitative theory of differential equations has been developed rapidly in the last decades, and there has been a great deal of work on the oscillatory behavior of differential equations; see e.g. (Agarwal et al 2010 ; Beqiri and Koci 2012 ; Bihari 1963 ; Elabbasy and Elsharabasy 1997 ; Elabbasy and Elhaddad 2007 ; Grace et al 1984 , 1988 ; Grace and Lalli 1987 , 1989 , 1990 ; Grace 1989 , 1990 , 1992 ; Greaf and Spikes 1986 ; Graef et al 1978 ; Lee and Yeh 2007 ; Kamenev 1978 ; Kartsatos 1968 ; Li and Agarwal 2000 ; Meng 1996 ; Nagabuchi and Yamamoto 1988 ; Ohriska and Zulova 2004 ; Ouyang et al 2009 ; Philos 1983 , 1984 , 1985 ; Remili 2010 ; Salhin 2014 ; Tiryaki and Basci 2008 ; Tiryaki 2009 ; Temtek and Tiryaki 2013 ; Yan 1986 ; Yibing et al 2013a , [ b ]; Zhang and Wang 2010 ).…”