http://en.wikipedia.org/wiki/Field_hockey>.
http://www.teamusa.org/USA-Field-Hockey.aspx>.
http://www.teamusa.org/USA-Field-Hockey/Features/2012/September/13/10-quirky-field-hockey-facts-for-National-Field-Hockey-Day.aspx>.
http://lower.usm.k12.wi.us/special/phy_ed/basic_fh_rules.htm
http://fieldhockey.isport.com/fieldhockey-guides/field-hockey-rules-regulations
http://www.uri.edu/personal/tcas8605/
http://www.nfhs.org/content.aspx?id=3282
http://www.abc.net.au/unleashed/3887922.html
http://www.webmd.com
http://orthoinfo.aaos.org
http://mayoclinic.org
Dr. Timothy E. Fitzgerald M.D.
http://www.teamusa.org/USA-Field-Hockey.aspx>.
http://www.teamusa.org/USA-Field-Hockey/Features/2012/September/13/10-quirky-field-hockey-facts-for-National-Field-Hockey-Day.aspx>.
http://lower.usm.k12.wi.us/special/phy_ed/basic_fh_rules.htm
http://fieldhockey.isport.com/fieldhockey-guides/field-hockey-rules-regulations
http://www.uri.edu/personal/tcas8605/
http://www.nfhs.org/content.aspx?id=3282
http://www.abc.net.au/unleashed/3887922.html
http://www.webmd.com
http://orthoinfo.aaos.org
http://mayoclinic.org
Dr. Timothy E. Fitzgerald M.D.