Convert from supergalactic to galactic coordinates palSupgal
de Vaucouleurs, de Vaucouleurs, & Corwin, Second Reference Catalogue of Bright Galaxies, U. Texas, page 8.
Systems & Applied Sciences Corp., Documentation for the machine-readable version of the above catalogue, Contract NAS 5-26490.
(These two references give different values for the galactic longitude of the supergalactic origin. Both are wrong; the correct value is L2=137.37.)