Грамоты Великого Новгорода и Пскова
[Official Documents of Velikii Novgorod and Pskov]

Edited by S. N. Valk. Moscow: Izdatel'stvo Akademii Nauk SSSR, 1949.

A comprehensive collection of legal and diplomatic documents that cover most of the later period of Novgorod and Pskov's rule over the Russians. An excellent source for diplomatic accounts including many examples of how Russian names were spelled by foreignors in their dealings with the Russians.