Grant, C., Claassen, N. and Viljoen, M. 2006. Stress response of the autonomic nervous system on skydiving and freefall. Suid-Afrikaans Tydskrif vir Natuurwetenskap en Tegnologie / <i>South African Journal of Science and Technology</i&gt;. 25, 1 (Sep. 2006), 32-39. DOI:https://doi.org/10.4102/satnt.v25i1.142.