Census of Population and Housing, 1990 [United States]: Summary Tape File 1A

The codebook and database dictionary for all parts except Puerto Rico (Parts 80 and 81) and the database dictionary for the Puerto Rico data, are ASCII text files, and the codebook for Puerto Rico is provided as a Portable Document Format (PDF) file. The PDF file format was developed by Adobe Systems Incorporated and can be accessed using PDF reader software, such as the Adobe Acrobat Reader. Information on how to obtain a copy of the Acrobat Reader is provided through the ICPSR Website on the Internet.