Zhu, Yao Chen, Algebraic Independence of Certain Values of Exponential Function, Acta mathematica Sinica. English series (Print) , 22(2), 2006, pp. 571-576
The algebraic independence of e.1,.,e.s is proved, where .1, . . . , .s are certain gap series or power series of algebraic numbers, or certain transcendental continued fractions with algebraic elements