Varde, Denmark (since November 17, 1969)San Mateo City Council resolution to adopt Varde as a sister city. November 17, 1969. Retrieved on February 18, 2016. Toyonaka, Osaka Prefecture, Japan (since October 8, 1963)"San Mateo and Toyonaka Celebrate 50 Years" in the 2013 Late Summer Edition of the San Mateo City Newsletter. Retrieved on February 18, 2016.
Varde, Denmark (since November 17, 1969)San Mateo, City Council resolution to adopt Varde as a sister city. November 17 1969. Retrieved on February 18, 2016. Toyonaka, Osaka Prefecture, Japan (since October 8, 1963)"San Mateo and Toyonaka Celebrate 50 Years" in the 2013 Late Summer Edition of the San Mateo City Newsletter. Retrieved on February 18, 2016.