Technical Explanation of the Protocol signed at Chelsea on September 21, 2007, amending the Convention between the United States of America and Canada with Respect to Taxes on Income and on Capital done at Washington on September 26, 1980, as amended by the Protocols done on June 14, 1983, March 28, 1994, March 17, 1995, and July 29, 1997. URL: www.treasury.gov/resource-center/tax-policy/treaties/Documents/tecanada08.pdf.