@article{RISC203,
author = {C. Schneider},
title = {{The summation package Sigma: Underlying principles and a rhombus tiling application}},
language = {english},
journal = {Discrete Math. Theor. Comput. Sci.},
volume = {6},
number = {2},
pages = {365--386},
isbn_issn = {ISSN 1365-8050},
year = {2004},
refereed = {yes},
length = {22},
url = {http://www.dmtcs.org/volumes/abstracts/dm060212.abs.html}
}