@article{02074134, title = {Eigenstructure of the equilateral triangle. II: The Neumann problem.}, journal = {Mathematical Problems in Engineering}, volume = {8}, year = {2002}, pages = {517-539}, doi = {10.1080/1024123021000053664}, zbl = {1122.35312}, language = {en}, url = {http://dml.mathdoc.fr/item/02074134} }
McCartin, Brian J. Eigenstructure of the equilateral triangle. II: The Neumann problem.. Mathematical Problems in Engineering, Tome 8 (2002) pp. 517-539. doi : 10.1080/1024123021000053664. http://gdmltest.u-ga.fr/item/02074134/