Depo-Provera Injections - Emory University School of Medicine fact sheet lists advantages and disadvantages of the "birth-control shot". - http://www.gynob.emory.edu/familyplanning/depo.cfm
Lunelle (Monthly Shot) - Feminist Women's Health Center's info on use, cautions, missed shots, advantages and disadvantages. - http://www.fwhc.org/birth-control/lunelle.htm
Depo Provera (3-Month Shot) - Feminist Women's Health Center's info on use, your health, advantages, disadvantages, preventing coercion, knowing your options. - http://www.fwhc.org/birth-control/bcdepo.htm