1. Living Microorganisms in ancient rocks;Jour. Bact.,1931
2. Are there living bacteria in stony meteorites;Amer. Mus. Novit.,1932
3. Further evidence of the amazing longevity of bacteria in coal;Science,1934
4. Bacteria in travertine from the Yellowstone;Jour. Bact.,1935
5. tVber das vorkommen von bakterien in kohlenfldzen;Biochem. Zeitsch.,1932