.
http://pratyeka.org/rock/
http://drjosephrock.blogspot.com/
http://www.peopleandplaces.de/joseph_rock.htm
http://huntbot.andrew.cmu.edu/HIBD/Departments/Archives/Archives-HR/Rock.shtml
http://genealogy.wikia.com/wiki/Joseph_Francis_Rock_(1884-1962)
http://www.npr.org/programs/re/archivesdate/1999/geocentury/
http://www.si.edu/archives/archives/findingaids/FARU7287.htm
http://homepage.univie.ac.at/helmut.lukas/rock.PDF (site en allemand)

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