Ekaterina Shemyakova, Franz Winkler. Approximate factorization of linear partial differential operators: full system of invariants for order three. ACM Comm. Computer Algebra, 40(2):34-35, 2006. [doi]
@article{ShemyakovaW06,
title = {Approximate factorization of linear partial differential operators: full system of invariants for order three},
author = {Ekaterina Shemyakova and Franz Winkler},
year = {2006},
doi = {10.1145/1182553.1182555},
url = {http://doi.acm.org/10.1145/1182553.1182555},
researchr = {https://researchr.org/publication/ShemyakovaW06},
cites = {0},
citedby = {0},
journal = {ACM Comm. Computer Algebra},
volume = {40},
number = {2},
pages = {34-35},
}