TY - CPAPER AU - David Hummer CY - London, England DA - 00/1983 N1 - JILA Pub. 2573 PB - Dordrecht, D. Reidel Publishing Co. PP - London, England PY - 1983 TI - Radiative transfer problems in planetary nebulae UR - http://adsabs.harvard.edu/full/1983IAUS..103..211H ER -