Levels of texts
The foundational books in the Hanafī school fall into three categories:
1] Ḍāhir al-Riwāyah or al-Aṣl
2] Nawādir
3] Nawāzil or Wāq’iāt or Fatāwā
Ḍāhir al-Riwāyah consists of the six canonical books of Muhammad ibn Hasan Shaybānī. They have been transmitted from him through multiple contiguous chains of transmission [tawātur or mashhūr]. These six canonical books are: Jām’i al-Ṣaghīr, Jām’i al-Kabīr, Siyar al-Ṣaghīr, Siyar al-Kabīr, Ziyādāt and Mabsūṭ. They all contain narrations of Imams Abu Hanifah, Abu Yusuf and Muhammad and at times contain narrations of Abu Hanifahs other students like Hasan ibn Ziyad and Zufar.
Micropaedia 