Finite-temperature Wigner solid and other phases of ripplonic polarons on a helium film Serghei N. Klimin, Jacques Tempere, Vyacheslav R. Misko and Michiel Wouters Eur. Phys. J. B, 89 8 (2016) 172 Published online: 01 August 2016 DOI: 10.1140/epjb/e2016-70149-8