求助几篇英文文献，谢谢！
1.Determination of sulphur in coal products by inductively coupled plasma atomic emission spectrometry
Sergio Caroli, A. Farina Mazzeo, A. Laurenzi, O. Senofonte and N. Violante
J. Anal. At. Spectrom., 1988, 3, 245 - 248,

2.Determination of the nature of organic sulphur in a high organic sulphur coal
Provence; Provence; France; France; Francia; Crétacé sup;
Coal science and technology 11, 13-14, Elsevier, 1987.

3.Sulphur Determination in Coal by Proton Activation Analysis
Authors: S. Landsberger ab;  A. Giovagnoli c;  J. L. Debrun c; Ph. Albert c
International Journal of Environmental Analytical Chemistry, Volume 16, Issue 4 March 1984 , pages 295-303

4.Fast non-destructive determination of iron and sulphur in coal by means of neutron radiative capture
Z. Janout1, J. Koníek1, S. Pospíil1, M. Vobecký2 and R. Drahoovský
Journal of Radioanalytical and Nuclear Chemistry
Volume 136, Number 6 423-435