APA-referens (7:e uppl.)

Spring, H. M. (1940). Boiler operator's guide: Construction, operation, inspection, and maintenance of steam boilers, with 310 typical steam engineer's examination questions and answers. McGraw-Hill Book Company.

Chicago-referens (17:e uppl.)

Spring, Harry Mortimer. Boiler Operator's Guide: Construction, Operation, Inspection, and Maintenance of Steam Boilers, with 310 Typical Steam Engineer's Examination Questions and Answers. New York: McGraw-Hill Book Company, 1940.

MLA-referens (8:e uppl.)

Spring, Harry Mortimer. Boiler Operator's Guide: Construction, Operation, Inspection, and Maintenance of Steam Boilers, with 310 Typical Steam Engineer's Examination Questions and Answers. McGraw-Hill Book Company, 1940.