TY - JOUR AU - John Burnett AU - R Gupta AU - U Griesmann C2 - Applied Optics DA - 2002-01-01 LA - en M1 - 41 PB - Applied Optics PY - 2002 TI - Absolute refractive indices and thermal coefficients of CaF2, SrF2, BaF2, and LiF near 157 nm ER -