@article{MM2_1980__32_154731,
     author = {Dieter Pumpl\"un},
     title = {Initial {Morphisms} and {Monomorphisms.}},
     journal = {Manuscripta mathematica},
     pages = {309--334},
     publisher = {mathdoc},
     volume = {32},
     year = {1980},
     zbl = {0466.18001},
     url = {http://geodesic.mathdoc.fr/item/MM2_1980__32_154731/}
}