Kamal Poorrezaei. Two Proofs of Graves's Theorem. The American Mathematical Monthly, 110(9):826-830, 2003. [doi]
@article{Poorrezaei03, title = {Two Proofs of Graves's Theorem}, author = {Kamal Poorrezaei}, year = {2003}, url = {http://www.jstor.org/stable/3647801}, researchr = {https://researchr.org/publication/Poorrezaei03}, cites = {0}, citedby = {0}, journal = {The American Mathematical Monthly}, volume = {110}, number = {9}, pages = {826-830}, }