Franchini, F; Its, A R; Jin, B-Q; Korepin, V E (2007). «Ellipses of constant entropy in theXYspin chain». Journal of Physics A: Mathematical and Theoretical40 (29): 8467. Bibcode:2007JPhA...40.8467F. doi:10.1088/1751-8113/40/29/019.
Its, A. R.; Jin, B. -Q.; Korepin, V. E. (2006). «Entropy of XY Spin Chain and Block Toeplitz Determinants». En I. Bender, ed. Fields Institute Communications, Universality and Renormalization50. p. 151. Bibcode:2006quant.ph..6178I.
Franchini, F; Its, A R; Jin, B-Q; Korepin, V E (2007). «Ellipses of constant entropy in theXYspin chain». Journal of Physics A: Mathematical and Theoretical40 (29): 8467. Bibcode:2007JPhA...40.8467F. doi:10.1088/1751-8113/40/29/019.