Anderson, Elizabeth T. (May–June 1978). „Plague in the Continental United States, 1900–76”. Public Health Reports93 (3), 297–301. o. PMID349602. PMC1431896.
Anderson, Elizabeth T. (May–June 1978). „Plague in the Continental United States, 1900–76”. Public Health Reports93 (3), 297–301. o. PMID349602. PMC1431896.