of the analyte element in a sample by characteristic radiation
from other elements in the sample resulting in an enhancement of the signal measured.
PAC, 1980, 52, 2541
(Nomenclature, symbols, units and their usage in spectrochemical analysis - IV X-ray emission spectroscopy)
on page 2547
IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997). XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic, J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8. doi:10.1351/goldbook