1. Barrett, E.A.M. (1990). Rogers' science-based nursing practice. In E. A. M. Barrett (Ed.), Visions of Rogers' science based nursing (pp. 31-44). New York: National League for Nursing.
2. Butcher, H.K. (1994). The unitary field pattern portrait method: Development of a research method for Rogers' science of unitary human beings. In M. Madrid, & E. A. M. Barrett (Eds.), Rogers' scientific art of nursing practice (pp. 397-429). New York: National League for Nursing.