Results of inverse variance (I-V, black), Kolmogorov-Smirnov (K-S, blue), and Fourier Transform (F-T, red) statistical tests applied to subset of 11 periods marked with asterisks in Appendix A. The three tests point to the existence of a period spacing of 40.58 s in WD 1310+583, which can be associated to ℓ = 1 modes. The presence of the subharmonic of this spacing at ∼20 seconds is also apparent.