Cita APA (7th ed.)

(1930). Manual on street traffic signs, signals and markings. [s.n.].

Cita Chicago (17th ed.)

Manual on Street Traffic Signs, Signals and Markings. Washington: [s.n.], 1930.

Cita MLA (9th ed.)

Manual on Street Traffic Signs, Signals and Markings. [s.n.], 1930.