The principal work on the bandora is Lyle Nordstrom, The Bandora: Its Music and Sources (Harmonie Park Press, 1992).
List of bandora sources
A list of historical sources of cittern music, with downloadable facsimiles where available, can be found at the Lute Library: www.lutelibrary.com/print-sources/instrument/wire#bandora
Downloadable tablature for bandora
Nancy Carlin's Grounds and Divisions pages: www.groundsanddivisions.info/bandora.html