Campbell NA, Reece JB (2004). Biology, 7th Edition. Benjamin Cummings. ISBN 978-0-8053-7146-8. Cite has empty unknown parameter: |coauthors= (bantuan)
Yijia Boa, Erik T. Nilsen (1988). "The Ecophysiological Significance of Leaf Movements in Rhododendron Maximum". Ecology. 69 (5): 1578–87. Cite has empty unknown parameter: |month= (bantuan)