Here is an article that provides information about ENP certification. This was written in 2013, which is the same year that the ANCC approved ENP certification.
Hoyt, K. Sue PhD, RN, FNP-BC, CEN, FAEN, FAANP, FAAN; Ramirez, Elda G. PhD, RN, FNP-BC, CEN, FAEN; Proehl, Jean A. RN, MN, CEN, CPEN, FAEN Section Editor(s): Hoyt, K. Sue; Proehl, Jean A.
An interesting article that opines about the DNP. Here's a fairly provocative quote:
"When viewed together, doctorally prepared nurses do not spend the majority of their time in direct patient care, but rather in research (11%), education (32%), and administration (30%). With these demanding roles, they cannot be expected to maintain expert levels of clinical competence required for teaching APN students. While research and practice are critical components of nursing, each requires a different skill set and education."
This is an excellent overview of NP history and practice changes written by Arlene W. Keeling PhD, RN, FAAN. It includes a historical narrative for the NP role that includes key figures (Lillian Wald, Mary Breckenridge, Loretta Ford) with seminal legislation, challenges to the practice, and future implications.