Similarity reductions of nonisospectral kp equation by a direct method

On bases of the direct method developed by Clarkson and Kruskal [J. Math. Phys. 27 (1989) 2201], the (2+1)-dimensional nonisospectral Kadomtsev- Petviashvili (KP) equation has been reduced to three types of (1+1)-dimensional partial differential equations. We focus on solving the third type of reduction and dividing them into three subcases, from which we obtain rich solutions including some arbitrary functions.