@article{GDZPPN00205843X, title = {Symmetry of Linking Coefficients.}, journal = {Commentarii mathematici Helvetici}, volume = {39}, year = {1964}, pages = {259-270}, zbl = {0127.13703}, url = {http://dml.mathdoc.fr/item/GDZPPN00205843X} }
Haefliger, A.; Steer, B. Symmetry of Linking Coefficients.. Commentarii mathematici Helvetici, Tome 39 (1964) pp. 259-270. http://gdmltest.u-ga.fr/item/GDZPPN00205843X/