Miller, Lectures on the Philosophy of Law, Lect. 5.
Herkless, Jurisprudence, ch. 10.
Russell, Social Reconstruction, ch. 4.
Spencer, Justice, ch. 12.
Kohler, Philosophy of Law, Albrecht's translation, 120-133.
Maine, Ancient Law, ch. 8.
----, Early History of Institutions (American ed.), 98-118.
----, Early Law and Custom (American ed.), 335-361.
Duguit, in Progress of the Law in the Nineteenth Century (Continental Legal History Series, Vol. XI), 129-146.
Wagner, Volkswirthschaft und Recht, besonders Vermögensrecht (1894).