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• FEDERER, H., (1969), Geometrik Measure Theory, Springer-Verlag, New York (p. 52-57).
• FEDERER, H. AND MORSE, A.P., (1943), Some properties of measurable functions, Bull., Am., Math., Soc., 49, 270-277.
• GOLMOGOROV, A.N. AND FOMİN, S. V., (1970), Introduction to Real Analysis, Revised English Edition, Translated and Edited by Silverman, R. A., 270 Madison Avenue, New York, p. 255-283.
• MURRAY, R. S., (1969), Real Variables Lebesgue Measure and Integration With Applications to Fourier Series, Schaum’s Outline Series, Mc Graw- Hill Book Company, New York, p. 30-40.