diff --git a/bilby/gw/psi4_waveform_generator.py b/bilby/gw/psi4_waveform_generator.py
index 0ae087c0209611dca4ee9141f27554c7ccd7c1ea..a3286317cf40c694c021cc7abebca2ce1cb8811c 100644
--- a/bilby/gw/psi4_waveform_generator.py
+++ b/bilby/gw/psi4_waveform_generator.py
@@ -63,16 +63,19 @@ class Psi4_WaveformGenerator(WaveformGenerator):
             self.is_psi4_model = False
 
         # Correction factor between derivative and differencing
+        # Details please refers to the article: arxiv:2205.15029
         # The argument in the correction factor: 2π kΔf Δt
         phase = 2 * np.pi * self.frequency_array / self.sampling_frequency
 
+        ## This correction_factor depends whether the data is strain or psi4,
+        ## the first is for psi4, (A5) in the article; and
+        ## the second is for strain, see (A4).
         self.correction_factor = \
-            # (A5) in the draft
             (1 - np.cos(phase)) / (0.5 * phase * phase) \
                 if self.is_psi4_model else \
-            # (A4) in the draft
             2 * self.sampling_frequency * self.sampling_frequency * (np.cos(phase) - 1)
 
+
         self._cache = dict(parameters=None, FD_waveform=None, TD_waveform=None)