1. BARR AND BUCHANAN 1912 Iowa State College Eng. Exper. Sta. Bull. 26.
2. BEITERINCK
1895 Centralbl. f. Bakt. 2 Abt. 1 3.
3. Arch. f;BURGER;Hyg.,1914
4. BURNET AND WEISSENBACH 1915 Compt. rend. de Soc. de Biol. 78 565-568.
5. CLARK
1913 Rept. Mass. State Bd. of Health 251.