APA (7th ed.) Citation

Costa, L. (2009). 20th Century Esfinge (Sphinx) solving the riddles at CLEF 2005.

Chicago Style (17th ed.) Citation

Costa, Luís. 20th Century Esfinge (Sphinx) Solving the Riddles at CLEF 2005. 2009.

MLA (8th ed.) Citation

Costa, Luís. 20th Century Esfinge (Sphinx) Solving the Riddles at CLEF 2005. 2009.

Warning: These citations may not always be 100% accurate.