Hollingsworth, D. (1954). Rocks in the roadway; a treatise on police public relations, by a police officer, for police officers. s.n.
Cita Chicago (17th ed.)Hollingsworth, Dan. Rocks in the Roadway; a Treatise on Police Public Relations, by a Police Officer, for Police Officers. Chicago: s.n, 1954.
Cita MLA (9th ed.)Hollingsworth, Dan. Rocks in the Roadway; a Treatise on Police Public Relations, by a Police Officer, for Police Officers. s.n, 1954.
Atenció: Aquestes cites poden no estar 100% correctes.