A four-volume set of books explores the Harappan Civilization under the series title Indus Age. The first volume appeared in November 1996 as Indus Age: The Writing System, published by the University of Pennsylvania.
The book begins with a review of the Mature Harappan and the place of writing in it. A typology of Harappan glyptics is presented in well-illustrated detail, followed by discussions of the possible survival of the Harappan script in later South Asian writing systems: Megalithic graffiti, the Brahmi script and symbols on punch marked coins. The centerpiece of the book is a review of over forty research efforts on the Indus script: G. R. Hunter, 1929: The First Rigorous Treatment of the Script; Sir Flinders Petrie, 1932: Reading the Script as Egyptian Hieroglyphics; Bedrich Hrozny, 1939: A Great Decipherer Takes on the Indus Script; The Russian Team, 1965: Computers and the Indus Script; The Finnish Team, 1969: More Dravidian, More Computers; S. R. Rao, 1982: The Harappans Invent the Alphabet; Walter A. Fairservis, Jr., 1992: Harappan Chiefdoms.
The current state of knowledge on the Indus script highlights the lack
of agreement among those attempting its decipherment, and the fact that
no one has developed an independent test to check the veracity of the
many claims. This assessment leads to three principles on which future
research on the writing system should proceed: 1) more thorough research
on the form of the writing system and its orthography, development of an
authoritative sign-list 2) study of the script through many small scale
research efforts 3) use multiple lines of inference so that identical
conclusions developed from two or more independent lines of reasoning can
test the claims of decipherment.