src/ZF/AC/document/root.bib

clarified example settings for Proof General;

@ARTICLE{paulson-gr,
  author = {Lawrence C. Paulson and Krzysztof Gr\c{a}bczewski},
  title = {Mechanizing Set Theory: Cardinal Arithmetic and the Axiom of Choice},
  journal = {Journal of Automated Reasoning},
  year = {1996},
  volume = {17},
  number = {3},
  pages = {291-323},
  month = dec}

@Book{rubin&rubin,
  author	= {Herman Rubin and Jean E. Rubin},
  title		= {Equivalents of the Axiom of Choice, {II}},
  publisher	= "North-Holland",
  year		= 1985}