These source materials appeared between 1940 and 1960 CE.

Synergy ExplorersBeyond Human Knowledge: A Consideration of the Unexplained in Man and Nature by Rudolf von Urban, MD (1958)

A physician offers his views on the electromagnetic exchange during intercourse and its potential.

Nature, Man and Woman by Alan Watts (1958)

Popular mystic Alan Watts shares his thoughts on tantra.

The Mystery of Sex by Charles Waldemar (1958)

German author discusses making of sexual union a psychic union.

Essay by Aldous Huxley (1956)

A discussion of the practice of sex without orgasm in historical terms.

The Chanson Affair (1950-1952)

Fascinating account of a modern movement promoting the Synergy concept in France and Belgium.

L’Étreinte Réservée: Témoignage des Époux by Paul Chanson (1951)

French and Belgian couples share their experiences with Synergy-style sex in this French book.

The Perfect Matrimony: Why Sex and Religion are Inseparable by Samael Aun Weor (1950)

Colombian author who founded the modern Gnostic Movement shares his synthesis of sexual spiritual wisdom.

Art D’Aimer et Continence Conjugale by Paul Chanson (1949)

[In French] This book promoting Synergy-style sex caused such a stir in France and Belgium that the Catholic Church suppressed its publication.

Sex Perfection and Marital Happiness by Rudolf von Urban, MD (1949)

Freudian psychiatrist explains why orgasm is not essential to sex happiness, and may be detrimental.

Thinking and Destiny: Being the Science of Man by Harold Waldwin Percival (1946)

A metaphysical look at the human condition and the role of sex.

If you cannot find what you want, for material before 1940 try 1900 CE – 1940 CE. For items after 1960 try 1960 CE – 2000 CE.