Greetings were sent to these two sisters(?) in Rom. 16: 12; the names were fairly common.
Citation for Tryphena and Tryphosa
Citation styles are based on the Chicago Manual of Style, 15th Ed., and the MLA Style Manual, 2nd Ed..
MLA
"Tryphena and Tryphosa." In A Dictionary of the Bible. Ed. W. R. F. Browning. Oxford Biblical Studies Online. May 18, 2013. <http://www.oxfordbiblicalcstudies.com/article/opr/t94/e1962>.
Chicago
"Tryphena and Tryphosa." In A Dictionary of the Bible. , edited by W. R. F. Browning. Oxford Biblical Studies Online, http://www.oxfordbiblicalcstudies.com/article/opr/t94/e1962 (accessed May 18, 2013).