@article{AM2_1997__54_3_137700,
     author = {H. Stetkaer},
     title = {Functional equations on abelian groups with involution.},
     journal = {Aequationes mathematicae},
     pages = {144--172},
     publisher = {mathdoc},
     volume = {54},
     number = {3},
     year = {1997},
     zbl = {0899.39007},
     url = {http://geodesic.mathdoc.fr/item/AM2_1997__54_3_137700/}
}