http://pec.lib.wvu.edu/record/P11571942Temperature movements of rhododendron petioles.Journal article reprint from: <em>Proceedings, West Virginia Academy of Science</em>, 1942. Also issued as: <em>West Virginia University bulletin </em>, 44:no.9 (1944:Mar.). Ritchie, Don.Rhododendrons.Rhododendrons--Frost resistance.14256