1. History of Islam in Vietnam
[By http://www.angelfire.com/vt/vietnamesemuslims/hstry.html]

The exact dates of Islam's spread in Indo-China is not known for certain. However, generally speaking, Islam arrived in Indo-China before it reached China during the Tang Dynasty (618-907). It was introduced by merchants from the Muslim world who sailed along the coastal cities. The following is a map and a quote from "Arab Seafaring" by George F. Hourani: 

2.Islam in Vietnam [By Wikipedia] 

Islam in Vietnam is primarily the religion of the Cham people, a minority ethnic group related to Malays; however, roughly one-third of the Muslims in Vietnam are of other ethnic groups. However, there is a community describing themselves of mixed ethnic origins (Cham, Khmer, Malay, Minang, Viet, Chinese and Arab), who practice Islam and are also known as Cham, or Cham Muslims, around the region of Chau Doc in the Southwest. 

3.Islam’s Journey Into Southeast Asia [By IslamOnline(IOL)]

  Defined as the region of land between India to the west, China to the north, and the Pacific Ocean to the east, Southeast Asia today comprises 10 countries: Brunei, Cambodia, Indonesia, Laos, Malaysia, Burma, the Philippines, Singapore, Thailand (Siam), and Vietnam.

4. Muslims of Vietnam
[By Tan Jo Hann, Malaysian writer ]

 Ho Chi Minh City--More than 1,000 years ago, the first Vietnamese embraced Islam and charted the religion's unique path into this Indo chinese country. Today Vietnamese Muslims claims that there are about 65,000 Muslims in Southern Vietnam, with at least 5,000 believers living in Ho Chi Minh City alone. There are about 15 mosques and Muslim places of worship in the capital city with at least 3 of them frequented by Muslims from Malaysia, Indonesia, India and Pakistan respectively.

5. Vietnam-Asia   [By Strategic Network]

MUSLIM POPULATION IN JAPAN
	Religion	Year 2000
	Buddhist	43220860
	Christian	6514260
	Ethnic Religion	6466360
	Chinese folk	878150
	Bahai	319330
	Muslim	558820
	Asian new	4470570
	Asian new	17403300
	Total	79831650

6. Vietnam-Champa Relations and the Malay-Islam Regional Network in the 17th–19th Centuries
[By Danny Wong Tze Ken ]
 
Historical relations between Vietnam and the kingdom of Champa was a very long- standing affair characterized by the gradual rise of the Vietnamese and the decline of the Chams. The relationship began as early as the second century CE, when the Chams started a kingdom called Lin-yi, covering the area between the land of the Viet people in the north and Nanchao in the south. The historical consciousness of both peoples includes wars and conflicts between the two over a period of fifteen centuries before the kingdom of Champa was incorporated under Vietnamese rule in 1693. Thereafter, the lands of the Chams were settled by Vietnamese through a series of land settlement programs introduced by the Vietnamese ruling houses.