* Bondsonline
http://www.bondsonline.comovides charts and historical data that compare various bond market sectors, for example,
a comparison of the 30-year treasury bonds, ten-year treasury notes, and the Dow Jones
Industrial Average, or a comparison of tax-free municipal yields as a percentage of U.S.
treasury yields.
* Federal Reserve Bank of St. Louis http://stls.frb.org all the monthly interest rates for
each type of treasury security. Files for specific treasuries (for example, the one-year
Treasury bill rate auction average) are downloadable and zipped.
* Moody's Investor Services http://www.moodys.com provides long-term corporate
bond yield averages based on bonds with maturities of 20 years and longer. Corporate bond
averages are sorted into average corporate, average industrial, and average public utility
groups, and by bond ratings.