From 1935 on he turned his attention to the newly excavated archeological sites of Mohenjo-Daro and Harappa: he was particularly keen on deciphering the inscriptions of the so-called Indus Valley civilization. He wrote numerous articles on the topic,  summing up finally his research in what will remain his master piece: Studies in Proto-Indo-Mediterranean Culture (1953) in which he proposed a solution to the mysterious script of Mohenjo-Daro, and established cultural links between the Indus Valley Civilization, the Sumerian-Egyptian civilization and the ancient Mediterranean cultures.
From 1935 onward, this individual focused on the archeological sites of Mohenjo-Daro and Harappa; he was particularly interested in deciphering the inscriptions from the Indus Valley civilization. He published numerous articles about the subject, culminating in his major work "Studies in Proto-Indo-Mediterranean Culture" (1953), where he proposed a solution to the script of Mohenjo-Daro and established connections between the Indus Valley Civilization, Sumerian-Egyptian civilization, and ancient Mediterranean cultures.