Church Records
Church records are available at this web site: http://www.lvva-raduraksti.lv/en.html.
CENSUS
1897 Census (see under Russia).
FAMILYSEARCH
Link to online sources for Latvia: https://familysearch.org/learn/wiki/en/Latvia_Online_Genealogy_Records
MAPS
Maps of Latvia can be found at this site: https://latvianhistory.com/old-latvian-maps/ [Includes other maps in Russian].