@article{RISC2953,
author = {C. Schneider},
title = {{Simplifying Sums in ${\Pi}{\Sigma}^*$-Extensions}},
language = {english},
journal = {J. Algebra Appl.},
volume = {6},
number = {3},
pages = {415--441},
isbn_issn = {ISSN: 0219-4988},
year = {2007},
note = {Preliminary version online},
refereed = {yes},
length = {26}
}