@article{NM_2004_XLIX_3-4_a6,
     author = {Nikola Aleksandrov},
     title = {Cosine {Theorem}},
     journal = {Nastava matematike},
     pages = {76 },
     publisher = {mathdoc},
     volume = {XLIX},
     number = {3-4},
     year = {2004},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/NM_2004_XLIX_3-4_a6/}
}