Voir la notice de l'article provenant de la source Czech Digital Mathematics Library
@article{UM_1997__5_4_a3, author = {Calda, Emil}, title = {P\v{r}ihr\'adkov\'y princip (tradi\v{c}n\v{e} i netradi\v{c}n\v{e})}, journal = {U\v{c}itel matematiky}, pages = {220--223}, publisher = {mathdoc}, volume = {05}, number = {4}, year = {1997}, language = {cz}, url = {http://geodesic.mathdoc.fr/item/UM_1997__5_4_a3/} }
Calda, Emil. Přihrádkový princip (tradičně i netradičně). Učitel matematiky, Tome 05 (1997) no. 4, pp. 220-223. http://geodesic.mathdoc.fr/item/UM_1997__5_4_a3/