c.w.-intracavity difference frequency generation (I.D.F.G.) by non-collinear mixing of three waves in two laser resonators Tran-Ba-Chu, R. Fischer et A.J. BouvierJ. Phys. France, 46 12 (1985) 2083-2091DOI: https://doi.org/10.1051/jphys:0198500460120208300
