A book in Arabic shows the creed of the four Imams: Abu Hanifa, Malek, Shafeai, and Ahmad ibn Hanbal, which is in harmony with the Quran and the Sunnah, without any difference between them about any aspect of the Islamic belief.
About the legitimacy of what some people do in mosques in certain ceremonies and after prayers in congregational way as someone utters the remebrance and others repeat after him