1. H.P. Yule, in J.R. DeVoe (Ed.), NBS Special Publication 312, 1969, p. 1155.
2. J. Turkstra, M.C.J. Van Rensburg and W.J. DeWet, PEL-204, 1970.
3. Activation Analysis in Geochemistry and Cosmochemistry;Yule,1971
4. Experimental data on photopeak integration methods in activation analysis