GLS periodograms of the RV data of HD 27894 with FAP levels of 10%, 1%, and 0.1% calculated from a bootstrap analysis. Panel a): the HARPS RVs resulted in many significant peaks especially at long periods. Panel b): after removal of the RV signal from planet d (P_b = 5174 days), the dominant peaks left are at 18.0 and 36.7 days (due to planets b and c), and at 12.0 and 57.1 days (aliases). Panel c): no significant peaks are left after fitting a 3PDM (see Table 1).