Wu, T.; Li, Y.; Hekker, S.: New Asteroseismic Scaling Relations Based on the Hayashi Track Relation Applied to Red Giant Branch Stars in NGC 6791 and NGC 6819. Astrophysical Journal 781, 44 (2014)

Hekker, S.; Mazumdar, A.: Solar-like oscillations in subgiant and red-giant stars: mixed modes. Proceedings of the International Astronomical Union 301, pp. 325 - 331 (2014)