@article{10_21136_CPM_1968_108660,
     author = {Kart\'ak, Karel},
     title = {On endomorphisms of the direct sum of two modules},
     journal = {\v{C}asopis pro p\v{e}stov\'an{\'\i} matematiky},
     pages = {117--120},
     year = {1968},
     volume = {93},
     number = {1},
     doi = {10.21136/CPM.1968.108660},
     mrnumber = {0236163},
     zbl = {0155.35303},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.21136/CPM.1968.108660/}
}