Summary: This paper, using the method of B. G. Zhang [Funkc. Ekvacioj. Ser. Int. 28, 93-101 (1985; Zbl 0578.34046)], is concerned with first-order functional-differential equations
Some new oscillation criteria are established and corresponding results by Ch. Tian and B. G. Zhang [Bull. Lond. Math. Soc. 31, No. 2, 196-206 (1999; Zbl 0933.34076)] are improved.