Liota, Lalpha, Lbeta and Lgamma X-ray production cross-sections for 4 elements, 74less than or equal toZless than or equal to90, at 10 different energies in the range 11-22 keV have been measured. The effect of Coster-Kronig transitions on fluorescence cross-sections for L X-ray line has been studied. Absolute values of L X-ray cross-sections have been calculated with incorporation of the enhancement due to the Coster-Kronig effect. The experimental enhancement factors tend to be smaller than those predicted by theory. (C) 2003 Elsevier Ltd. All rights reserved.