Reishtein, Judith L. (2005), "Relationship Between Symptoms and Functional Performance in COPD", Research in Nursing and health, 28, 39-47.
- Leidy, N.K. (1995) , "The Functional Performance Inventory".
- Buysse, D.J., C.F. Reynolds, and T.H. Monk (1989), "The Pittsburgh Sleep Quality Index: A new instrument for psychiatric practice and research", Psychiatry Research, 28, 193-213. [Endnote]