Assalam o alaikum.

You need not to study a separate book for Ottoman Caliphate.
You should study only a few topics like;
Muhammad Al Fatih
Suleman the Magnificent and
Ottoman Tanzimat or Reforms.

For these, you may find Sohail Bhatti's book good enough which has discussed only these topics in the Ottoman Chapters. Rest, you can download material from internet also.


Good Luck

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