Cassingham KM, Sills EO, Pattanayak SK, Mansfield CA. Voluntary conservation of North Carolina's natural heritage. J For. 2002;100(5):16-23.
Estrada CA, Unterborn JN, Price J, Thompson D, Gibson L. Judging the effectiveness of clinical pathways for pneumonia: the role of risk adjustment. Eff Clin Pract. 2000 Sep 1;3(5):221-8.