On the Boundedness and the Stability of Some Differential Equations of the Fourth Order

Stability and boundedness to certain differential equations of fourth order with multiple delays

“…The work of Cartwright [6] made very important scientific contributions to the qualitative theory of differential equations of higher order, and this paper may be accepted as a starting basic point for the later researches done on the topic. Later, many researchers investigated the stability and boundedness of solutions of various nonlinear differential equations of fourth order without delay, see, the book of Reissig et al [24] as a survey and the papers of Abou-El-Ela& Sadek [1], Adesina&Ogundare [3], Burganskaja [5], Cartwright [6],Chukwu [7], Ezeilo [8][9][10], Ezeilo&Tejumola [11], Harrow [12], Hu [13], Kaufman & Harrow [15], Lalli & Skrapek [16][17][18], Lin et al [19], Ogundare&Okecha [20], Ogurcov [21,22], Skidmore [27], Skrapek&Lalli [28], Tejumola [29], Tunç [31-34, 36,37], Wu&Xiong [44] and the references cited.…”