Coba jelasin Rujukan dari Caterpillar Inc. dalam bahasa melayu dong

Orlemann, Eric C. Caterpillar Chronicle, The History of the World's Greatest Earthmovers. Minneapolis, MN: MBI Publishing Company, 2000.

Antique Caterpillar Machinery Owners Club

Photos of early Holt machinery

Caterpillar Tractor Company Photograph Collection at Baker Library Historical Collections, Harvard Business School

Syarikat yang ditubuhkan pada 1925