Here are entered works on the community of believers in Islam. Works on the religion of which Muhammad is the prophet are entered under Islam. Works on the group of countries in which the majority of the people are Muslims or in which Islam is the established religion are entered under Islamic countries. Works on the cultural system or civilization erected on the foundation of the religion Islam are entered under specific headings according to period covered, e.g. Civilization, Islamic (for the medieval period); Islamic countries--Civilization (for the modern period and general works).