https://www.astroart-forum.net/forum/viewtopic.php?f=5&t=933&p=3589&sid=fbf25c3c5c309d1a335e213c1afe1333
Polar alignment by declination drift - Astroart Forum
polar alignmentdeclinationdriftforum
https://research.bangor.ac.uk/en/publications/tonal-association-and-tonal-alignment-evidence-from-greek-polar-q/
Tonal association and tonal alignment: evidence from Greek polar questions and contrastive...
tonalassociationalignmentevidencegreek