For a discussion of the use of mutual, See common, mutual. An additional suggestion: avoid using mutual with words that imply working or being together."Mutual cooperation" is a wordy phrase from which mutual should be deleted. How often is mutual needed with words such as collaboration, concert, collusion, complicity, partnership, fraternity, fellowship, federation, tie-up, teamwork, unison, comradeship, combination, and concurrence?
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See common, mutual
Dictionary of problem words and expressions. Harry Shaw. 1975.