Arabic: Al-Farooq is a book by Shebli Al-Numani. It has 479 pages and it states the separation between truth & falsehood.
Other Sources:
Attributes of Servants of Allah – Quran Surah Furqan Verse 63-65
Authenticating Hadith (Sayings of the Prophet) – An Overview
The story how Jesus (Eesa) was asked to prove his miracles
Caliphate capitals (Madinah, Kufah, Damascus)