Joseph P. Pickett; etal., eds. (2000). "Bittern". The American Heritage Dictionary of the English Language (4thed.). Boston: Houghton Mifflin. Archived from the original on 2005-01-16. Retrieved 2006-07-04.
Joseph P. Pickett; etal., eds. (2000). "Bittern". The American Heritage Dictionary of the English Language (4thed.). Boston: Houghton Mifflin. Archived from the original on 2005-01-16. Retrieved 2006-07-04.