Ben-Or, M. (1983), "Lower bounds for algebraic computation trees", Proc. 15th Annu. Symp. Theory of Computing, pp. 80–86, doi:10.1145/800061.808735, ISBN0-89791-099-0.
Grigoriev, Dima; Vorobjov, Nicolai (1996), "Complexity lower bounds for computation trees with elementary transcendental function gates", Theor. Comput. Sci., 157 (2): 185–214, doi:10.1016/0304-3975(95)00159-X.