@article{Heise1989,
	title = {Upper and lower bounds for the partition function of lattice models},
	author = {Michael Heise},
	day = {01},
	journal = {Physica A: Statistical Mechanics and its Applications},
	month = {Jun},
	number = {2},
	pages = {983--999},
	url = {http://www.sciencedirect.com/science/article/B6TVG-46FX4GK-D3/1/1aef01f98e125c02f1195f65921c1c84},
	volume = {157},
	year = {1989},
	biburl = {http://www.bibsonomy.org/bibtex/22cbcd3203899a20bc6e83235b31f58ee/smicha},
	description = {Physica A},
	keywords = {imported }
}