Wa `alaykum as-salamu wa rahmatullahi wa barakatuh

 

You are allowed to copy books or materials as long as you have permission to make use of it for personal research and study as stipulated by the owners.

You are not allowed to buy pirated copies sold in the market. For doing so is not at all different from buying stolen goods. We may do well to remember that aiding or abetting or condoning a sin is also a sin.

 

Therefore, you should always try to borrow such books or materials from libraries – if you cannot afford to buy them.

 

Allah Almighty knows best.