@article{IM_1991__105_3_143907,
     author = {J.A. Thas and S.E. Payne and Van Maldeghem},
     title = {Half {Moufang} implies {Moufang} for finite generalized quadrangles.},
     journal = {Inventiones mathematicae},
     pages = {153--156},
     publisher = {mathdoc},
     volume = {105},
     number = {3},
     year = {1991},
     zbl = {0708.51010},
     url = {http://geodesic.mathdoc.fr/item/IM_1991__105_3_143907/}
}