O'Hara, V. (1990). The fitness option: Five weeks to healing stress (2nd ed.). Dawn.
Dyfyniad Arddull ChicagoO'Hara, Valerie. The Fitness Option: Five Weeks to Healing Stress. 2nd ed. Nevada City, CA: Dawn, 1990.
Dyfyniad MLAO'Hara, Valerie. The Fitness Option: Five Weeks to Healing Stress. 2nd ed. Dawn, 1990.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.