Reinhold Ebertin's (often abbreviated as CSI or COSI ) is considered a seminal text in 20th-century astrology, specifically for the school of Cosmobiology . First published in 1940, it remains a staple reference for practitioners due to its systematic approach to planetary midpoints. Core Concepts and Methodology
of the 1972 English edition for free through their "Controlled Digital Lending" program. Open Library : A companion to the Internet Archive, Open Library Open Library : A companion to the Internet
If you cannot find a free legal copy, consider these budget-friendly alternatives: Solar Biology Unlocking the Secrets of Astrology: A
The Combination of Stellar Influences is essentially a comprehensive encyclopedia of "planetary pictures". For every possible combination of three planets (where one planet sits at the midpoint of two others), Ebertin provides: Ebertin provides: : Uses 0°
: Uses 0°, 45°, 90°, 135°, and 180° for high-tension accuracy. Solar Biology