1. Abd al-Majid al-Hakim (2007). Brief Explanation of Civil code, Part 1, Sources of obligation, 2nd edn, Legal Library: Baghdad
2. Abd al-Majid al-Hakim (2009). The Brief Explanation of Civil code, part 2, 2nd edn, Legal Library: Baghdad
3. Abd al-Razzaq Ahmad al-Sanhouri (1998). Al-Waseet in Explanation of the New Civil code, Part 1, Volume 2, 3rd edn, Al-Halabi legal Publications: Beirut
4. Abd al- Moneim Faraj Al-Sada (1974). Theory of Contracts in the Laws of Arab Countries, Egyptian, Lebanese, Syrian, Iraqi, Libyan, Kuwaiti, and Sudanese Law, 1st edn, Dar Al-Nahda Al-Arabiya: Beirut
5. Abd al- Hai Hijazi (1982). The General Theory of Obligation According to Kuwaiti Law, Comparative Study, Part 1 Sources of Obligation, Vol. 1, The Theory of Obligation - Contract Analysis, 1st edn, Kuwait University Publications: Kuwait