1970:
1. in books with statistics
2. ASI 1973 2473-2
1980:
1. in brown binding on top of map case
2. ASI 1983 2551-1
3. on microfiche in bottom drawer of last CIS fiche cabinet - incl. block and enumeration districts; MN MSAs only.
1990:
1. Back behind Y4s by Emergency Exit; they're sorted by county. MN only
2. http://www.census.gov/geo/www/maps/descriptwindows/census_blockmaps.htm
2000:
1. http://www.census.gov/geo/www/maps/descriptwindows/census_blockmaps.htm
2. American FactFinder