@article{PT78, <br>AUTHOR = {Paul, W.J. and Tarjan, R.E.},<br>TITLE = {Time-Space Trade-Offs in a Pebble Game},<br>VOLUME = {10}, <br>YEAR = {1978},<br>PAGES = {111--115}, <br>SERIES = {Acta Informatica 1978},<br>EE = {http://www.springerlink.com/content/rq90v3u24j842105/},<br>}