@article{MOMA_1981__92_178053,
     author = {George Szeto and Yuen-Fat Wong},
     title = {On {Free} {Quadratic} {Extensions} of {Rings.}},
     journal = {Monatshefte f\"ur Mathematik},
     pages = {323--328},
     publisher = {mathdoc},
     volume = {92},
     year = {1981},
     zbl = {0461.16008},
     url = {http://geodesic.mathdoc.fr/item/MOMA_1981__92_178053/}
}