The Spanish pioneers and the California missions.

http://www.archive.org/details/spanishpioneersa009682mbp

The mission as a frontier institution in the Spanish american colonies, by Herbert E. Bolton.

http://www.archive.org/details/missionasfrontie00boltrich

The conquest of the continent, by Hugh Latimer Burleson

http://www.archive.org/details/conquestofcontin00burluoft

Mexico coming into light

Boston University Theology Library