Popular Lectures on Scientific Subjects By: Hermann von Helmholtz

Popular Superstitions, and the Truths Contained Therein By: Herbert Mayo

Porto Rico: The Land of the Rich Port By: Joseph B. Seabury

Practical Talks by an Astronomer By: Harold Jacoby

Prehistoric Men By: Robert J. Braidwood

Prejudices, First Series By: H. L. Mencken

Preliminary Report on Neo-Fascist and Hate Groups By: House Un-American Activities Committee

Princes and Poisoners: Studies of the Court of Louis XIV By: Frantz Funck-Brentano

Psychology of Peoples: Its Influence on Their Evolution By: Gustave Le Bon

Psychology of the Unconscious By: Carl Gustav Jung

Psychotherapy By: Hugo Münsterberg

Queer Little Folks By: Harriet Beecher Stowe

Radioisotopes and Life Processes By: Renato Baserga

Radioisotopes in Medicine By: Earl W. Phelan

Raiders of the Universes By: Donald Wandrei

Random Reminiscences of Men and Events By: John D. Rockefeller

Recollections of Imperial Russia By: Meriel Buchanan

Red Reign: The True Story of an Adventurous Year in Russia By: Kellogg Durland

Report of the National Advisory Commission on Civil Disorders (Kerner Commission Report) By: National Advisory Commission on Civil Disorders

Report of the President's Commission on the Accident at Three Mile Island By: President's Commission on the Accident at Three Mile Is

Report on Securing and Growing the Digital Economy By: The Commission on Enhancing National Cybersecurity

Report to the President by the Presidential Commission on the Space Shuttle Challenger Accident By: Presidential Commission on the Space Shuttle Challenger

Republic (version 2) By: Plato (Πλάτων)

Researches into the Physical History of Man By: James Cowles Prichard

Revolted Woman By: Charles George Harper

Rip Foster Rides the Gray Planet By: Harold L. Goodwin

Romance of Modern Astronomy By: Hector Macpherson

Romance of Modern Electricity By: Charles R. Gibson

Romance of Modern Engineering By: Archibald Williams

Romance of Modern Geology By: Edwin Sharpe Grew

Romance of Modern Invention By: Archibald Williams

Romance of Modern Mechanism By: Archibald Williams