Answered By: ask crisslibrary Last Updated: May 06, 2015 Views: 5
This guide http://libguides.unomaha.edu/c.php?g=100267&p=649709 provides a list of all the databases likely to have articles on the subject. It might take a while, but entering different combinations of keywords and subject terms like "private," "commercial," "differences," "benefits," etc., should produce some results that ou can use for furher research. The guide also provides lins to statistical sources that could be of use.
In person: Make an appointment with a Research Librarian.