00292nam a2200097Ia 4500008004100000082002000041100003500061245006400096260002600160300000800186140113s9999    xx            000 0 und d  a311:631.95   N4  a"Leigh, R.A. & Johnston, A.E."  aLong term experiments in agricultural & Ecological sceinces  a1994bCABIcCambridge  a428