The important of knowing synonyms

It is very important to know the synonym of the words. Especially when we make research. For example, I search for a book that I know it is about Umar's administration. The book in Arabic. So, I search 'Umar' and 'idarah'. When I look through the catalog, I can't find it, but I am sure it is there as my supervisor told me so. I search again and just look up 'idara'. And I found among all, one book titled 'Aulawiyyat al-Faruq fi al-Idarah wa al-Qadha'. If I do not know that al-Faruq is the title given to Umar al-Khattab, I might not know that this is the book I am searching for.

Hmm... synonym.. synonym. I need to make my own thesaurus of research after this. I think so.