The Rhythm Cycles in Marriage
Periodical Abstention in Wedlock. A complete theoritical and practical introduction to the Knaus-Ogino method for the use of married people and their advisers
The rhythm of sterility and fertility in women
A discussion of the physilogical, practical and ethical aspects of the discoveries of Dr. K. Ogino, Japan, and Prof. H. Knaus, Germany, regarding the periods when conception is impossible and when possible.
The "Safe Periode" as a birth control measure
