www.becominghuman.org

www.mnh.si.edu/anthro/humanorigins/index.htm

www.archaeologyinfo.com/evolution.htm

www.handprint.com/LS/ANC/homofs.html

www.msu.edu/%7Erobin400/humanevolution.html

http://www.talkorigins.org/faqs/homs/species.html#antecessor