Bernstein, Leilah (December 31, 1999). "L.A. Then AND NOW". Los Angeles Times. Archived from the original on February 27, 2017. Retrieved February 27, 2017.
"Figures Show California's Motoring Supremacy". Touring Topics. 8 (2). Los Angeles, California: Automobile Club of Southern California: 38–39. March 1916. Archived from the original on March 15, 2023. Retrieved May 9, 2021.
California, Historical Society of Southern (1901). The Quarterly, Volumes 5-6. Historical Society of Southern California. p. 223. Archived from the original on March 15, 2023. Retrieved May 9, 2021.
"Counties". 2020 U.S. Census Gazetteer Files. United States Census Bureau. Archived from the original on October 26, 2021. Retrieved September 3, 2021.
"San Diego County QuickFacts". United States Census Bureau. April 1, 2020. Archived from the original on September 24, 2021. Retrieved September 3, 2021.
"Orange County QuickFacts". United States Census Bureau. April 1, 2020. Archived from the original on January 28, 2021. Retrieved September 3, 2021.
"Riverside County QuickFacts". United States Census Bureau. April 1, 2020. Archived from the original on February 1, 2021. Retrieved September 3, 2021.
Bernstein, Leilah (December 31, 1999). "L.A. Then AND NOW". Los Angeles Times. Archived from the original on February 27, 2017. Retrieved February 27, 2017.
"Figures Show California's Motoring Supremacy". Touring Topics. 8 (2). Los Angeles, California: Automobile Club of Southern California: 38–39. March 1916. Archived from the original on March 15, 2023. Retrieved May 9, 2021.
California, Historical Society of Southern (1901). The Quarterly, Volumes 5-6. Historical Society of Southern California. p. 223. Archived from the original on March 15, 2023. Retrieved May 9, 2021.
"Counties". 2020 U.S. Census Gazetteer Files. United States Census Bureau. Archived from the original on October 26, 2021. Retrieved September 3, 2021.
"San Diego County QuickFacts". United States Census Bureau. April 1, 2020. Archived from the original on September 24, 2021. Retrieved September 3, 2021.
"Orange County QuickFacts". United States Census Bureau. April 1, 2020. Archived from the original on January 28, 2021. Retrieved September 3, 2021.
"Riverside County QuickFacts". United States Census Bureau. April 1, 2020. Archived from the original on February 1, 2021. Retrieved September 3, 2021.