Rethinking Tradition in Modern Islamic Thought by Daniel Brown
One of the best books out there. Charts the history of hadith/sunna within Islam, with a focus on the debates surrounding their legitimacy.
Summary here: https://pressthat.wordpress.com/2007/05/09/rethinking-tradition-in-modern-islamic-thought-by-daniel-brown/
Read book online here: https://www.scribd.com/document/116836545/Rethinking-Traditions-in-Modern-Islamic-Thought-Daniel-w-Brown
Hadith Studies 
Thanks for all the great hadith texts and for Muhammad Asad’s Principals of State etc. via your Scribd a/c (hadn’t been able to find that anywhere). I’m trying to track down a copy of Rashid Rida’s Al-Khilafa aw al-Imamat al-‘Uzma (probably not your field)…
The download link seems to be dead. Could you kindly provide an alternative link?
try here , right click https://ahadithstudies.files.wordpress.com/2010/12/brown-rethinking-tradition-islamic.pdf