1. Meron configurations in the two-dimensional O(3) σ-model;Gross,1977
2. SU (N) invariant nonlinear σ-models;Eichenherr,1978
3. The secret long range force in quantum field theories with instantons;Lüscher,1978
4. A 1/N expandable series of nonlinear σ-models with instantons;D'Adda,1978