1. Andrillat,Y. and Houziaux,L.: 1967,J.Obs.50,107=Publ.OHP 9,n°11.
2. Conti,P.S. and Leep,E.M.: 1974, Astrophys.J. 193, 113.
3. Frost,S.A. and Conti,P.S.: 1976,in A.Slettebak(ed.),Be and shell stars, D.Reidel Publ.Co.,Dordrecht-Holland, 139.
4. Polidan,R.S. and Peters,G.J.: 1976,in A.Slettebak(ed.),Be and shell stars, D.Reidel Publ.Co.,Dordrecht-Holland, 59.