Jensen, Joan M. The price of vigilance, [electronic resource] / by Joan M. Jensen.. — Chicago, : Rand McNally, [1969, c1968]. — 367 p. : illus., ports. 22 cm. Bibliographical references included in "Sources" (p. 316-353). LCCN: 68030929 Subjects--Corporate Names: American Protective League. Subjects--Topical Terms: Subversive activities--United States. LC Class. No.: E743.5 / .J4 Dewey Class. No.: 940.4/86/73