Income from royalties

Income from Royalties will be taxed under Income from Other Sources. We can claim general expenses incurred exclusively for the same u/s 57 of the Income Tax Act.

Suppose, I receive royalty of 20% of value(sale price) of books, since we can claim a deduction u/s 80 QQB of 15% of the sale price of the books before claiming such expense. Can I claim the expense u/s 57 and avail decuction u/s 80 QQB as well? Isn't there any double decuction of the expenses I incurred?