Petersen diagram of the 0.61 group. The previously discovered Galactic members of the group (Pietrukowicz et al. 2013; Rathour et al. 2021) are marked with orange asterisk and triangles. Black lines connect the values for the same star. Red symbols denote stars for which we found multiple peaks for the 0.61 frequency group in the same light curve. The stars that are also members of the 0.68 group are marked with circles.