(1)
Shoji Yamamoto and Kei-ichi Funase, Fermionic versus bosonic descriptions of one-dimensional spin-gapped antiferromagnets, Low Temp. Phys. 31, 740–747, (2005) [Fiz. Nizk. Temp. 31, 974-983, (2005)] DOI: https://doi.org/10.1063/1.2008134.