Multiple periodic solutions for delay differential equations with a general piecewise constant argument

This paper is concerned with the existence of multiple periodic solutions for some delay differential equations with a general piecewise constant argument. Under some sufficient conditions, we establish the existence of two and three nonnegative periodic solutions for the addressed delay differential equation with piecewise constant argument. Also, we apply one of our main results to a Nicholson rsquo;s blowflies type model.