TY  - RPRT
TI  - O(3) nonlinear sigma model and the topological distinction between integer- and half-integer-spin antiferromagnets in two dimensions.
AU  - FD Haldane
PY  - 1988
DO  - 10.1103/physrevlett.61.1029
UR  - https://pubmed.ncbi.nlm.nih.gov/10039496/
ID  - 10039496
ER  -