Can somebody recommend me some free online resources to read about material history of ancient India - before Maurya? On Wikipedia there was surprisingly little on the material history of India before 4th century BC, which is kind od awkward, as I have no idea what exactly happened there for the previous centuries between "Indo Aryans go from cows to sedentary lifestyle" and "gigantic Maurya empire emerges, already with writing, urban centers, monumental architecture, army giving Seleucus run for his money" etc. I only know about religious and philosophical transformations from this period, but it is annoying for my imagination to have no idea what levels of social complexity existed in Indian subcontinent between 1000 BC and 400 BC.