@article{10_21136_CPMF_1926_124054,
     author = {Friedrich, Jaroslav},
     title = {Demonstrace ve funkci praktika},
     journal = {\v{C}asopis pro p\v{e}stov\'an{\'\i} matematiky a fysiky},
     pages = {323--326},
     year = {1926},
     volume = {55},
     number = {3},
     doi = {10.21136/CPMF.1926.124054},
     language = {cs},
     url = {http://geodesic.mathdoc.fr/articles/10.21136/CPMF.1926.124054/}
}