Here are a few useful links having to do with Latvia and Brazil:
The Balts in Brazil, a paper by Vivian Gruber.
A Millenarian Migration: Varpa by Arnolds Karklis offers an excellent overview of the Baptist exodus to Brazil.
The Human Dignity and Social Exclusion Project: Latvia, offers a recent (1997), very dense overview of Latvian society.
Origins of Pentecostalism in Latvia (navigate down the page, starting with references 34+). Makes good reading.