The autotopism group of ap-primitive semifield plane of orderq 4

Let κ be a semifield plane of order q⁴ with kernel K≅GF(q²), where q=p^r, p is prime. Previously, Johnson determined the form of p-primitive semifield planes of order q⁴, q=p^r, and Cordero specified the form of autotopisms and proved the solvability of an autotopism group for the particular case q=p. The goal of the present article is to give an explication of the form of autotopisms and prove the solvability of an autotopism group in the general case. Translated fromAlgebra i Logika, Vol. 35, No. 3, pp. 334–344, May–June, 1996.