Does anyone know where I can find details, or a good article, about all of these slaves in India and Pakistan?

edit: the report itself lists the details.

Bonded labour is the greatest problem in Pakistan. The Asian Development Bank estimates that 1.8 million people are bonded labourers, though many NGOs place the estimate much higher.

India exhibits the full spectrum of different forms of modern slavery, from severe forms of inter-generational bonded labour across various industries to the worst forms of child labour, commercial sexual exploitation, and forced and servile marriage.