The appearance of writing in Iran* (scholarly/research)

Tokens, envelopes and clay tablets were the earliest principal media used by mankind. Tokens were first used for book keeping in the pre-historic period. Their evolution led to the invention of clay tablets that first included numbers, but later changed to economic ideo-numerical inscriptions (pictographs).The authors try to describe these writing evidences together with their geographical distribution, evolution, advantages and disadvantages, origin and chronology in Iran.