Boyer, Mary Jo. 
Math for nurses :  a pocket guide to dosage calculation and drug preparation /  Mary Jo Boyer.   - 8th ed.   - Philadelphia, Pa. ;  London :  Wolters Kluwer/Lippincott Williams & Wilkins,  c2013.   - xvi, 400 p. :  col. ill. ;  19 cm. +  1 conversion chart.