Live Science, "What Is Frankincense" LiveScience December 24, 2012 LiveScience December 24, 2012 https://www.livescience.com/25670-what-is-frankincense.html LiveScience December 24, 2012 boswellia sap LiveScience December 24, 2012 http://www.livescience.com/25670-what-is-frankincense.html frankincense LiveScience December 24, 2012 livescience.com