Assalam o Alaikum,
I would like to share with you two very useful and important research papers (No. 5-a and No. 5-b), prepared by Engr. Muhammad Ali Mirza of Jehlum, Pakistan.
Download from his official website, http://ahlesunnatpak.com/research-papers/
1st research paper: No. 5-a
Analysis of Rawafidh, Nawasib and Yazidis from Quran and Sahih Ahadith.
2nd research paper: No. 5-b
Real background of Tragedy of Karbala from Sahih Ahadith.
JAZAK Allah KHAIRAN.
إِنَّ أَصْدَقَ الْحَدِيثِ كِتَابُ اللَّهِ وَأَحْسَنَ الْهَدْىِ هَدْىُ مُحَمَّدٍ وَشَرَّ الأُمُورِ مُحْدَثَاتُهَا وَكُلَّ مُحْدَثَةٍ بِدْعَةٌ وَكُلَّ بِدْعَةٍ ضَلاَلَةٌ وَكُلَّ ضَلاَلَةٍ فِي النَّارِ