You may want to see:
Publication 597 Information on the United States-Canada Income Tax Treaty 901 U.S. Tax Treaties
See chapter 7 for information about getting these publications.taxmap/pubs/p54-021.htm#en_us_publink100047607
The United States has tax treaties or conventions with many countries. See Table 6-1 at the end of this chapter for a list of these countries.
Under these treaties and conventions, citizens and residents of the United States who are subject to taxes imposed by the foreign countries are entitled to certain credits, deductions, exemptions, and reductions in the rate of taxes of those foreign countries. If a foreign country with which the United States has a treaty imposes a tax on you, you may be entitled to benefits under the treaty.
Treaty benefits generally are available to residents of the United States. They generally are not available to U.S. citizens who do not reside in the United States. However, certain treaty benefits and safeguards, such as the nondiscrimination provisions, are available to U.S. citizens residing in the treaty countries. U.S. citizens residing in a foreign country may also be entitled to benefits under that country's tax treaties with third countries.
You should examine the specific treaty articles to find if you are entitled to a tax credit, tax exemption, reduced rate of tax, or other treaty benefit or safeguard.