The following books are used as resources for preparing these lectures. Please note that these books are copyrighted, so please purchase the books to support the authors.
1) Lost Islamic History - Firas Alkhateeb
2) Civilization of Faith - Dr. Mustafa al-Siba'i
3) Bidaya Wa Nihaya - Ibn Kathir
4) Al-Muqaddimah - Ibn Khaldun
5) Productivity Principles of Umar II - Ismail Kamdar