@article{MZ_1927__26_167930,
     author = {C. Burstin and W. Mayer},
     title = {\"Uber affine {Geometrie} {XLI:} {Die} {Geometrie} zweifach ausgedehnter {Mannigfaltigkeiten} {F2} im affinen {R4}},
     journal = {Mathematische Zeitschrift},
     pages = {373--407},
     publisher = {mathdoc},
     volume = {26},
     year = {1927},
     zbl = {53.0707.06},
     url = {http://geodesic.mathdoc.fr/item/MZ_1927__26_167930/}
}