Plangsangmas, T, Brown, J L, Thitaram, C, Silva-Fletcher, A T, Edwards, K L, Punyapornwithaya, V, Towiboon, P, Somgird, C, "Circadian Rhythm of Salivary Immunoglobulin A and Associations with Cortisol as A Stress Biomarker in Captive Asian Elephants (Elephas maximus)", Animals, 2020