2. Quasi-Primary Source Material, or the Auxiliary Sources of History.
(a) Historical geography, involving a consideration of the "origin, meaning, distribution, and changes of geographical names."
(b) Ethnology and sociology.
(c) Geology, paleontology, and physical geography.
(d) Paleography, or the science of ancient writings.
(e) Diplomatics, or treatises on official documents.
(f) Epigraphy, or the science of inscriptions.
(g) Numismatics, or the study of coins.
(h) Languages.
3. Secondary Authorities.