Robert Gottlieb and Irene Wolt Thinking Big: The Story of the Los Angeles Times, Its Publishers and Their Influence on Southern California, G.P. Putnam's Sons: NY, 1977. 603 pp. 1938, 1936
"A conspiracy of General Motors (GM) and several other companies provided the coup de grace for the transit system's deterioration. In 1936, a consortium of corporations, including General Motors, Standard Oil of California, Firestone Tire and Rubber, B.F. Phillips Petroleum and Mack Manufacturing Company, organized a company called National City Lines (NCL). NCL was in the business of converting existing electrical rail systems-trolleys and streetcars-to motorized buses.
"In 1938, NCL set up a West Coast affiliate called the Pacific City Lines (PCL), which immediately began to buy up the Los Angeles Railway system . . ." p. 252