Ji, 2016. Ji, Lei (2016). «Unionization, Market Structure, and Economic Growth». Southern Economic Journal82 (3): 935-951. doi:10.1002/soej.12111.
Abraham, Friedman y Thomas, 2008, pp. 1–11. Abraham, Steven E.; Friedman, Barry A.; Thomas, Randall K. (2008). «The Relationship Among Union Membership, Facets of Satisfaction and Intent to Leave: Further Evidence on the Voice Face of Unions». Employee Responsibilities and Rights Journal20 (1): 1-11. ISSN0892-7545. doi:10.1007/s10672-007-9061-z.
Abraham, Friedman y Thomas, 2008, pp. 1–11. Abraham, Steven E.; Friedman, Barry A.; Thomas, Randall K. (2008). «The Relationship Among Union Membership, Facets of Satisfaction and Intent to Leave: Further Evidence on the Voice Face of Unions». Employee Responsibilities and Rights Journal20 (1): 1-11. ISSN0892-7545. doi:10.1007/s10672-007-9061-z.