Ober, Aren: Midpoint Interpretation Simplified, 2nd Edition, Cotter Books, Cleveland OH USA, 2009. Witte, Alfred: Der Mensch, Ludwig Rudolph Verlag, Hamburg, Germany, 1975.
... Combination of Stellar Influences, Ebertin-Verlag, Aalen, 1972. ISBN 086690087X External links. Astrology Books by Reinhold Ebertin; Midpoint Astrology Books by Aren Ober (formerly ...