The use and abuse of the terms percent, parts per million and parts in 10^n

1. Mills I. M., Unity as a Unit, Metrologia, 1994/95, 31, 537-541. 2. Cvitaˇs T., Metrologia, 1996, 33, 35-39. 3. Quantities and Units, ISO Standards Handbook, 3rd ed., Geneva, International Organization for Standardization, 1993 [ISBN 92-67-10185-4]. 4. Mills I., Cvitaˇs T., Homann K., Kallay N., Kuchitsu K., Quantities, Units and Symbols in Physical Chemistry, IUPAC Green Book, 2nd ed, Oxford, Blackwell