@article{PDA_1976_6_1_a4,
     author = {Margherita Hack},
     title = {General {Properties} of the {Ap} {Stars}},
     journal = {Publications of the Department of Astronomy},
     pages = {31 - 34},
     publisher = {mathdoc},
     volume = {6},
     number = {1},
     year = {1976},
     url = {http://geodesic.mathdoc.fr/item/PDA_1976_6_1_a4/}
}