1. Lundberg GD. When to panic over abnormal values. MLO Med Lab Obs. 1972;4:47-54.
2. Kost GJ. Critical limits for emergency clinician notification at United States children's hospitals. Pediatrics. 1991;88:597-603.
3. Howanitz PJ, Steindel SJ, Heard NV. Laboratory critical values policies and procedures. Arch Pathol Lab Med. 2002;126:663-669.
4. Kost GJ. The challenges of ionized calcium: cardiovascular management and critical limits. Arch Pathol Lab Med. 1987;111:932-934.
5. Lum G. Evaluation of a laboratory critical limit (alert value) policy for hypercalcemia. Arch Pathol Lab Med. 1996;120:633-636.