  In this short paper we prove that the following two 1-dimensional families of
Artin-Schreier curves are supersingular: y^7 - y = x^5 + c.x^2 over F_7 y^5 - y
= x^7 + c.x over F_5 (for some parameter c). Our method is developed upon the
p-adic Dwork's method.
