James Harvey Young (29 Nov 2017). "Koch, William Frederick (1885-1967), physician and discoverer and promoter of new medications alleged to cure cancer and other diseases". American National Biography Online (بالإنجليزية). DOI:10.1093/ANB/9780198606697.ARTICLE.1201446. ISSN:1470-6229. QID:Q103866157.
James Harvey Young (29 Nov 2017). "Koch, William Frederick (1885-1967), physician and discoverer and promoter of new medications alleged to cure cancer and other diseases". American National Biography Online (بالإنجليزية). DOI:10.1093/ANB/9780198606697.ARTICLE.1201446. ISSN:1470-6229. QID:Q103866157.
James Harvey Young (29 Nov 2017). "Koch, William Frederick (1885-1967), physician and discoverer and promoter of new medications alleged to cure cancer and other diseases". American National Biography Online (بالإنجليزية). DOI:10.1093/ANB/9780198606697.ARTICLE.1201446. ISSN:1470-6229. QID:Q103866157.