reference
- A.E.Thierens, Elementen der Esoterische Astrologie, part Symbolen, page 178 - 187, published by Schors, Amsterdam, the Netherlands, isbn:90 6378 039-7
- A.E.Thierens, Elementen der Esoterische Astrologie, part Symbolen, page 178 - 187, published by Schors, Amsterdam, the Netherlands, isbn:90 6378 039-7