%0 Journal Article
%A Defever, F.
%A Deszcz, R.
%A Sentürk, Z.
%A Verstraelen, L.
%A Yaprak, S.
%T P.J. Ryan's problem in semi-Riemannian space forms
%J Glasgow mathematical journal
%D 1999
%P 271-281
%V 41
%N 2
%U http://geodesic.mathdoc.fr/articles/10.1017/S0017089599970969/
%R 10.1017/S0017089599970969
%F 10_1017_S0017089599970969