A Book of Jashar is quoted in Josh. 10: 13 and 2 Sam. 1: 18 and apparently consisted of songs and poems.
Citation for Jashar
Citation styles are based on the Chicago Manual of Style, 15th Ed., and the MLA Style Manual, 2nd Ed..
MLA
"Jashar." In A Dictionary of the Bible. Ed. W. R. F. Browning. Oxford Biblical Studies Online. May 23, 2013. <http://www.oxfordbiblicalcstudies.com/article/opr/t94/e982>.
Chicago
"Jashar." In A Dictionary of the Bible. , edited by W. R. F. Browning. Oxford Biblical Studies Online, http://www.oxfordbiblicalcstudies.com/article/opr/t94/e982 (accessed May 23, 2013).