Naturally speaking a dictionary of quotations on biology,

Eitemau Tebyg

• Naturally speaking : a dictionary of quotations on biology, /
  Cyhoeddwyd: (2001)
• The Merriam-Webster Dictionary of Quotations /
  gan: Merriam-Webster, Inc
  Cyhoeddwyd: (2004)
• The Oxford dictionary of quotations/
  Cyhoeddwyd: (1968)
• Dictionary of Quotations : Collected and Arranged and with Comments
  gan: Evans, Bergen, 1904-
  Cyhoeddwyd: (1978)
• The Penguin dictionary of quotations/
  gan: Cohen, J.M
  Cyhoeddwyd: (1968)