In response, the leadership of the missionary movement commissioned Hendrik Kraemer, the well-known Dutch missiologist then working as a missionary in Java, to write a book on the biblical and theological basis of the Christian attitude to other faiths. Kraemer’s The Christian Message in a Non-Christian World became the preparatory study book for the next international missionary conference in Tambaram, India, in 1938.
http://www.wcc-coe.org/wcc/what/interreligious/diction.html

Missiology: "the conscious, intentional, ongoing reflection on the doing of mission. It includes theory(ies) of mission, the study and teaching of mission, as well as the research, writing, and publication of works regarding mission" (Neely 2000, 633). "1. the study of the salvation activities of the Father, Son, and Holy Spirit throughout the world geared toward bringing the kingdom of God into existence, 2. the study of the worldwide church's divine mandate to be ready to serve this God who is aiming his saving acts toward this world" (Verkuyl 1978, 5).
http://www.missiology.org/missionsdictionary.htm