Pseudo-differential equations connected with p-adic forms and local zeta functions

We study the asymptotics of fundamental solutions of p-adic pseudo-differential equations of type (f (partial derivative, beta) + lambda)u = g, where f (partial derivative ,beta) is a pseudo-differential operator with symbol \f\(beta)(K), beta > 0, f is a form of arbitrary degree with coefficients in a p-adic field, lambda greater than or equal to 0, and g is a Schwartz-Bruhat function.