Further Reading:

Roger Wright, A Sociophilological Study of Late Latin

J.N. Adams, The Regional Diversification of Latin 200 BC-AD 600

J.N. Adams, Social Variation and the Latin Language

J.N. Adams, Bilingualism and the Latin Language

Jozsef Herman, Vulgar Latin

Roger Wright, Late Latin and Early Romance

James Clackson and Geoffrey Horrocks, The Blackwell History of the Latin Language