Existence of positive solutions for advanced equations with several terms , is investigated in the following three cases: (a) all coefficients are positive; (b) all coefficients are negative; (c) there is an equal number of positive and negative coefficients. Results on asymptotics of nonoscillatory solutions are also presented.
L. Berezansky. E. Braverman. "On Nonoscillation of Advanced Differential Equations with Several Terms." Abstr. Appl. Anal. 2011 (SI1) 1 - 14, 2011. https://doi.org/10.1155/2011/637142