1. Germ-Free Life and Gnotobiology;Luckey,1963
2. Germfree animals and their significance;Pleasants;Endeavour,1973
3. The Prolongation of Life: Optimistic Studies;Metchnikoff,1907
4. Gnotobiotics in science and medicine;Trexler;Vet. Rec.,1967
5. The Germ-Free Animal in Research;Pleasants,1968