Parpola, Asko and Koskenniemi, Seppo and Parpóla, Simo and Aalto, Pentti (1969):

Parpola, Asko - Koskenniemi, Seppo - Parpóla, Simo - Aalto, Pentti, Decipherment of the Proto-Dravidian Inscriptions of the Indus Civilization. A First Announcement (The Scandinavian Institute of Asian Studies, Special Publications No. 1). 72 p. Copenhagen 1969. The Scandinavian Institute of Asian Studies.