Saya mau tau Pautan luar dari Kuap. Jelaskan dalam bahasa melayu

Why Do We Yawn? The unexpected truth behind the science of yawning, LiveLeak (originally aired on Good Morning America), 30 Julai 2007

A Real Yawner: Causes, Concerns and Communications of the Yawn, Mary Bridget Reilly, University of Cincinnati, 23 Oktober 2003