Selected Reading
- Daniel TM: The P of the EL is C.J Lab Clin Med 110:127, 1987
- Hurst JW: The art of poor communication. Emory Univ J Med 4:281, 1990
- Stedman's Abbreviations, Acronyms and Symbols, 2nd ed. Lippincott Williams &Wilkins, Baltimore, 1999, p 79