00318nam a2200097Ia 4500008004100000082002200041100003500063245007200098260004200170300000800212140113s9999    xx            000 0 und d  a631.46:581.2   L2  a"Johnston, L. F. & Curl, E.A."  aMethods for Research on the ecology of soil -borne plant  pahtogens  a1972bBurgerss Publishing Co.cU.S.A.  a247