Official Catalogue of the Great Exhibition of the Works of Industry of All Nations, 1851. Corrected ed. London, [1851].

Oliver, John W. History of American Technology. NY, 1956.

Oppenheimer, Frank. The German Drawing Instrument Industry: History and Sociological Background // Journal of Engineering Drawing. № 20. Nov. 1956. P. 29–31.

Ormond, Leonee. Writing. London, 1981.

Pacey, Arnold. The Maze of Ingenuity: Ideas and Idealism in the Development of Technology. Cambridge, Mass., 1976.

Palatino, Giovambattista. The Tools of Handwriting: From … Un Nuovo Modo d’Imparare [1540]. Introduced, translated, and printed by A. S. Osley. Wormley, 1972.

The Pencil Collector. Various numbers.

Pentel of America, Limited. Pentel Brings an End to the Broken Lead Era with New «Super» Hi-Polymer Lead. [Sales catalogue insert.] Torrance, Ca., 1981.

Peterson, Eldridge. Mr. Berwald Absorbs Pencils // Printers’ Ink. № 171. May 2, 1935. P. 21, 24–26.

Petroski, H. On the Fracture of Pencil Points // Journal of Applied Mechanics. № 54. Sept. 1987. P. 730–733.

Petroski, H. Inventions Spurned: On Bridges and the Impact of Society on Technology // Impact of Science on Society. № 37 (№ 147, 1987). P. 251–259.

Petroski, H. To Engineer Is Human: The Role of Failure in Successful Design. NY, 1985.

Pevsner, N. The Term «Architect» in the Middle Ages // Speculum. № 17. 1942. P. 549–562.

Phillips, E. W. J. The Occurrence of Compression Wood in African Pencil Cedar // Empire Forestry Journal. № 16. 1937. P. 54–57.

Pichirallo, Joe. Lead Poisoning: Risks for Pencil Chewers? // Science. № 173. Aug. 6, 1971. P. 509–510.

Pigot and Company. London and Provincial New Commercial Directory, for 1827–28; Comprising a Classification of, and Alphabetical Reference to the Merchants, Manufacturers and Traders of the Metropolis, [etc.]. 3rd ed. London, [1827].

Pigot and Company. Metropolitan New Alphabetical Directory, for 1827; [etc.]. London, [1827].

Pinck, Dan. Paging Mr. Ross // Encounter. № 69. June 1987. P. 5–11.

Pliny. Natural History. With an English translation by H. Rackham. Cambridge, Mass., 1979.

Plot, Rob. Some Observations Concerning the Substance Commonly Called, Black Lead // Philosophical Transactions (London). № 20. 1698. P. 183.

Porter, Terry. The Pencil Revolution // Texas Instruments Engineering Journal. № 2. Jan. — Feb. 1985. P. 66.

Pratt, Joseph Hyde. The Graphite Industry // Mining World. July 22, 1905. P. 64–66.

Pratt, Sir Roger. The Architecture of Sir Roger Pratt, [etc.]. Edited by R. T. Gunther. Oxford, 1928.

Pye, David. The Nature and Aesthetics of Design. London, 1978.

Rance, H. F., editor. Structure and Physical Properties of Paper. NY, 1982.

Reed, George H. The History and Making of the Lead Pencil // Popular Educator. № 41. June 1924. P. 580–582.

Rees, Abraham. The Cyclopedia; or, Universal Dictionary of Arts, Sciences, and Literature. Philadelphia, n.d.

Rehman, M. A., and S. M. Ishaq. Indian Woods for Pencil Making // Indian Forest Research Leaflet. № 66. 1945.

Rehman, M. A., and Jai Kishen.