the following are the references of the book 'al-Mahdi':
1. the book 'esaaf-ar-raghebeen' is about the virtues of the holy prophet (s.a.w.a.) and his ahl-e-bayt (a.s.). its written by shaikh muhammad saban who died in the year 1206.
2. the book 'ja'ame-ul-lalif' is about the excellence of mecca and the construction of the holy mosque. its author is allama shaikh jamaluddin muhammad jarrullah-ibn-muhammad -ibn-nuruddin-ibn-abu bakr-ibn-ali zahiray qurshi makhzumi. this book was written in the year 950 hijri and was printed in the year 1276 in the printing-house of dar ehya-ul- kitab-ul-arabiya.
3. commentary on nahjul-balagha - written by a leading personality in literacy and history by the name of shaikh ezzuddin abu hamed abdul hamid-ibn-hebtullah mada'eni famous as ibne-abil hadid who died in the year 655 hijri. this book has been printed in four volumes in darul-kitab al-arabiya in egypt.
4. sahih bukhari - written by a leading traditionist abu abdullah muhamamd-ibn-isma' eel- ibn-ibrahim-ibn-mughaira who died in the year 256 hijri. this book has been printed in the year 1312 in the publishing-house of maimaniya in egypt.
5. sahih sunan mustafa - written by a leading traditionist abu dawoud sulaiman-ibn-asha'r sajestani who died in the year 357.
6. sahih tirmidhi - written by abu isa muhammad-ibn -surah who died in the year 278. this book was printed in the year 1310 at lucknow in india.
7. sawa'eq muharreqa - written by shaikh shahabuddin ahmad-ibn-hajar haisami against the people of innovation and heresy. he died in the year 974 in mecca. this book was printed in egypt in the year 1933.
8. eqdud-durar - written about the awaited imam by the great scholar abu badr shaikh jamaluddin yusuf ibn-yahya-ibn-ali-ibn-abdul aziz-ibn-ali muqaddasi, shafa'ee, selmi, damashqi who finished writing this book in the year 658 a.h. this book is the best and the most comprehensive book written by one sunni brethren in this regard. i have not come across the printed script of this book and perhaps it may not have been printed at all.