Leys, J., & Troester, R. R. (1989). Oral history interview with Jeff Leys.
Dyfyniad Arddull ChicagoLeys, Jeff, and Rosalie Riegle Troester. Oral History Interview with Jeff Leys. 1989.
Dyfyniad MLALeys, Jeff, and Rosalie Riegle Troester. Oral History Interview with Jeff Leys. 1989.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.