At the Seventh Level(1972)
(The third book in the Coyote Jones series)
A novel by Suzette Haden Elgin
In order for Abba to be admitted to the society of civilized planets, it had made slight improvements in its treatment of women. Until then, women were considered as not human, as a sort of necessary beast, but not more....As a result, one brilliant female had risen to the top, the Seventh Level. Thereby she had become the spiteful target of male fury, female envy, and finally of a deviously evil plot that might cost the world its status.
Used availability for Suzette Haden Elgin's At the Seventh Level
June 1972 : USA Mass Market Paperback