The books you cited will do very well for you. I was a contributor to the Mayberry book and his research is exemplary. Use his footnotes as sources for your program.

I would also add these:

Journal of the Secession Convention of Texas 1861. This is valuable for the flag presented to the convention as well as the argument between Texas and Louisiana over the flag of the Republic of Louisiana.

"A Fifteen Star Texas Flag: A banner Used at the Time of Secession - February 1861 and march 1861" by Frank Wilson Kiel. (Southwestern Historical Quarterly, January 2000, Vol. CIII, No. 3) This important essay covers the uniquely Texas secession flags, also called "lone star flags" due to the center star being large than the rest. These were typically on blue fields and examples can be found in Mayberry's book as well as Texas period newspapers. This circular star pattern also influenced one of the battle flag designs with the saltire (Southern cross) of which one or two are shown in the Maberry book. Another example, in a museum in Rockford, Illinois, taken at Arkansas Post by the 127th Illinois, is also of this pattern and is therefore probably from a Texas unit there.

"The Romantic Flags of Texas" by Mamie Wynne Cox. This essay still has its good stuff but much needs to be taken with a grain of salt.

"The Flags and Seals of Texas" by Charles A. Spain Jr. (South Texas Law Review, February 1992, Vol 33, No. 1). A scholarly treatise on Texas flag history by a member of the North America Vexillological Association.

"Unit Colors of the Trans-Mississippi Confederacy, parts 1-3" by Howard Michael Madaus. (Military Collector & Historian, Fall 1989, Vol. XLI, No. 3; Winter 1989, Vol. XLI, No. 4; Spring 1990, Vol. XLI, No. 1) This three part essay with illustrations along the lines of his seminal book on the Army of Tennessee flags, is loaded with Texas unit colors. One of the flags in the essay, the First National of the Warren Guards (Texas UDC Collection), I have since identified as being a company flag of the 16th Tennessee Infantry taken from their wagons in November 1863 near Chattanooga.

Please note one thing about the 1839 Texas republic/state flag; the vast majority of Texas Confederates were not born in Texas (same for Arkansas by the way - 85 per cent of those men were born elsewhere). Thus, in late 1860 when this flag starts showing up again some of the newspapers had to actually describe it so that all of the new immigrants would know what the flag was. Within the constant use of the phrase "lone star flag" this actually means possibly two flags; the Texas state flag or an example of the 15 star secession flags with the bigger center star.

Hope all of this is helpful.

Greg Biggs