1. [1] V.M. Khrapchenko, “Complexity of the realization of a linear function in the case of π-circuits,” Mathematical Notes, vol.9, pp.21-23, 1971.
2. [2] J. Håstad, “The shrinkage exponent of De Morgan formulas is 2,” SIAM J. Comput., vol.27, no.1, pp.48-64, Feb. 1998.
3. [3] A.E. Andreev, “On a method for obtaining more than quadratic effective lower bounds for the complexity of π-scheme,” Moscow University Mathematics Bulletin, vol.42, no.1, pp.63-66, 1987.
4. [4] S. Laplante, T. Lee, and M. Szegedy, “The quantum adversary method and classical formula size lower bounds,” Computational Complexity, vol.15, no.2, pp.163-196, 2006.
5. [5] T. Lee, “A new rank technique for formula size lower bounds,” Proc. 24th Annual Symposium on Theoretical Aspects of Computer Science (STACS 2007), Lect. Notes Comput. Sci. 4393, pp.145-156, 2007.