@article{GDZPPN002451476, title = {Spherical Probable Error (Spe) and its Estimation}, journal = {Metrika}, volume = {16}, year = {1970}, pages = {149-163}, zbl = {0209.50101}, url = {http://dml.mathdoc.fr/item/GDZPPN002451476} }
Singh, N. Spherical Probable Error (Spe) and its Estimation. Metrika, Tome 16 (1970) pp. 149-163. http://gdmltest.u-ga.fr/item/GDZPPN002451476/