TY - JOUR AU - E. Smith AU - C. Vidal AU - John Cooper BT - Journal of Research of the National Bureau of Standards N1 - JILA Pub. 457 PY - 1969 SP - 389 EP - 404 T2 - Journal of Research of the National Bureau of Standards TI - Classical path methods in line broadening. I. The classical path approximation UR - http://archive.org/details/jresv73An4p389 VL - 73A ER -