Sj. Cheng, CONSTRUCTION OF N=2 SUPERCONFORMAL ALGEBRA FROM AFFINE ALGEBRAS WITH EXTENDED SYMMETRY .1., letters in mathematical physics, 33(1), 1995, pp. 23-31
The purpose of this Letter is to use the idea of the Sugawara-Kac-Todo
rov construction of the N = 0 and N = 1 superconformal algebras to con
struct a very simple free-field realization of the N = 2 superconforma
l algebra.