Weidong Gao. Addition Theorems and Group Rings. Journal of Combinatorial Theory, Series A, 77(1):98-109, 1997. [doi]
@article{Gao97:1, title = {Addition Theorems and Group Rings}, author = {Weidong Gao}, year = {1997}, doi = {10.1006/jcta.1996.2731}, url = {http://dx.doi.org/10.1006/jcta.1996.2731}, researchr = {https://researchr.org/publication/Gao97%3A1}, cites = {0}, citedby = {0}, journal = {Journal of Combinatorial Theory, Series A}, volume = {77}, number = {1}, pages = {98-109}, }