International law -- Early works to 1800
Richard Zouch(e) 1590-1661
Samuel Freiherr von Pufendorf 1632-1694
Bijnkershoek, Cornelis van, 1673-1743
Wolff
Vattel, Emer de, 1714-1767
Martens, G. F. de/von (Georg Friedrich), 1756-1821.
Cornelius Van Bynkershoek : his role in the history of international law by 
Vattel's international law in a XXIst century perspective by MPEPIL starting point is entry
The Law Bod has the print copy of this encyclopedia at Internat 500 E56c, but the online version has had a number of updates since the work was printed.
The Power of Language in the Making of International Law the word sovereignty in Bodin and Vattel and the myth of Westphalia by 
The Empire of Civilization : the evolution of an imperial idea by 
The Invention of Custom: Natural Law and the Law of Nations, ca. 1550-1750 by Jay Treaty (Treaty of Amity, Commerce and Navigation between Great Britain and the United States, signed at London, 19 November 1794 52 CTS 243. (1841) I BSP 984)