@inproceedings{KPPY84, <br>AUTHOR = {Klawe, M. and Paul, W.J. and Pippenger, N. and Yannakakis, M.},<br>TITLE = {On Monotone Formulae with Restricted Depth},<br>YEAR = {1984},<br>PAGES = {480--487}, <br>BOOKTITLE = {Proc. 16th ACM-STOC }, <br>EE = {http://doi.acm.org/10.1145/800057.808717},<br>}