books.google.com - Many types of stars show conspicuous emission lines in their optical spectra. These stars are broadly referred to as emission line stars. Emission line stars are attractive to many people because of their spectacular phenomena and their amazing varieties and variability. This book offers general information...http://books.google.com/books/about/The_Astrophysics_of_Emission_Line_Stars.html?id=qt5sueHmtR4C&utm_source=gb-gplus-shareThe Astrophysics of Emission-Line Stars
