@article{JDM_1931__40_145875,
     author = {Vladimir Vranic},
     title = {\"Uber die sph\"arische {Trignometrie.}},
     journal = {Jahresbericht der Deutschen Mathematiker-Vereinigung},
     pages = {98--101},
     publisher = {mathdoc},
     volume = {40},
     year = {1931},
     zbl = {0001.15504},
     url = {http://geodesic.mathdoc.fr/item/JDM_1931__40_145875/}
}