%A Sugie Jitsuro %N 18 %D 2020 %L acta69522 %O Bibliogr.: 7. p. ; ĂśsszefoglalĂĄs angol nyelven %K DifferenciĂĄlegyenlet %T A remark on Philos-type oscillation criteria for differential equations %X The purpose of this short note is to call attention to expressions of Philostype criteria for the oscillation of solutions of a simple differential equation. A perfect square expression is used to obtain an evaluation that plays an essential role in the proof of Philos-type oscillation theorems. The required condition is pointed out when using the perfect square expression. To simplify the discussion, here we deal with two second-order linear differential equations, but its content is also applied to a variety of equations.