@article{GDZPPN00233447X, title = {Witt groups of real projective surfaces.}, journal = {Mathematische Annalen}, volume = {287}, year = {1990}, pages = {89-102}, zbl = {0692.14012}, url = {http://dml.mathdoc.fr/item/GDZPPN00233447X} }
Sujatha, R. Witt groups of real projective surfaces.. Mathematische Annalen, Tome 287 (1990) pp. 89-102. http://gdmltest.u-ga.fr/item/GDZPPN00233447X/