@article{JRAM_1969__0239_0240_150964,
     author = {J. Schmidt and V. Nov\'ak},
     title = {Direct decompositions of partially ordered sets with zero.},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {97--108},
     publisher = {mathdoc},
     volume = {0239_0240},
     year = {1969},
     zbl = {0188.04202},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1969__0239_0240_150964/}
}