`Abd al-Qadir Bada'uni book Muntakhab-ut-Tawarikh
But in spite of such wanton cruelty, Muslim power continued to decline till the Khaljis revived it after 1290 AD.
`Abd al-Qadir Bada'uni, quoted from Goel, Sita Ram (2001). The story of Islamic imperialism in India. ISBN 9788185990231 Ch. 6
Muntakhab-ut-Tawarikh