Sources

Henriksson, Markku. Route 66: A Road to America's Landscape, History, and Culture. Lubbock, TX: Texas Tech UP, 2014. Print.

Marshall, Rick. "Steinbeck's Cognitive Landscapes in ‘The Grapes of Wrath’: The Highway as Commentary on 1930s Industrialization." Steinbeck Review 8.1 (2011): 57-76. Web.

Steinbeck, John. The Grapes of Wrath. Harlow: Penguin, 2006. Print.

Steinbeck, John. The Harvest Gypsies: On the Road to the Grapes of Wrath. Berkeley: Heyday, 1988. Print.

Yogi, Stan, ed. Highway 99: A Literary Journey through California's Great Central Valley. Berkeley, Ca.: Heyday, 1996. Print.