A specific-heat "discontinuity" is observed in liquid He3 from 241 lb/in.2 to the melting pressure in the temperature range 2-3 mK.
Published in Physical Review Letters, ed. Gene D. Sprouse, Volume 30, Issue 6, 1973, pages 210-213.
Webb, R. A., Greytak, T. J., Johnson, R. T., & Wheatley, J. C. (1973). Observation of a second-order phase transition and its associated P - T phase diagram in Liquid He3. Physical Review Letters, 30(6), 210 - 213. DOI: 10.1103/PhysRevLett.30.210
© Physical Review Letters, 1973, American Physical Society