The United States Supreme Court has held that an individual employee who asserts a right contained in his collective- bargaining agreement is engaged in "concerted activity" within the meaning of section 7 of the National Labor Relations Act.
NLRB v. City Disposal Systems, Inc., 104 S. Ct. 1505 (1984).
Francis X. Matt III,
Labor Law - National Labor Relations Act - Section 7 - Concentrated Activity,
Duq. L. Rev.
Available at: https://dsc.duq.edu/dlr/vol23/iss4/17