SPONTANEOUS ACCELERATION OF FREELY ROTATING HELIUM II AS A MANIFESTATION OF A NEW TYPE OF QUANTUM PHASE TRANSITION E.L. Andronikashvili, J.S. Tsakadze and S.J. Tsakadze J. Phys. Colloques, 39 C6 (1978) C6-180-C6-181 DOI: 10.1051/jphyscol:1978680