László Lovász, Alexander Schrijver. Dual graph homomorphism functions. Journal of Combinatorial Theory, Series A, 117(2):216-222, 2010. [doi]
@article{LovaszS10, title = {Dual graph homomorphism functions}, author = {László Lovász and Alexander Schrijver}, year = {2010}, doi = {10.1016/j.jcta.2009.04.006}, url = {http://dx.doi.org/10.1016/j.jcta.2009.04.006}, tags = {graph-rewriting, rewriting}, researchr = {https://researchr.org/publication/LovaszS10}, cites = {0}, citedby = {0}, journal = {Journal of Combinatorial Theory, Series A}, volume = {117}, number = {2}, pages = {216-222}, }