• Author: Schmidt-Wellenburg, C. A. H. Biebach S. Daan G. H. Visser
• Title: Energy expenditure and wing beat frequency in relation to body mass in free flying Barn Swallows (Hirundo rustica)
• Year: 2007
• Reference Type: Journal Article
• Journal/Book Title: J Comp Physiol B
• Volume: 177
• Issue: 3
• Pages: 327-37
• Date of Publication: Thursday, 20 December 2007