‎"BLACKMAN, R. B.‎
‎Effect of Feedback on Impedance. - [BLACKMAN'S IMPEDANCE RELATION]‎

‎New York, American Telephone and Telegraph Company, 1943. 8vo. In the original printed blue wrappers. In ""The Bell System Technical Journal"", Volume XXII, Number 3, October, 1943. Entire issue offered. Light miscolouring to spine. A very fine fine and clean copy. Pp. 269-277. [Entire issue: Pp- 269-402.].‎

Reference : 47645

‎First printing of Blackman's influential paper on impedance feedback. ""The Blackman's impedance relation formula holds several unique and important features. First and most important is generality. The formula is truly universal and could be applied regardless of feedback topology. The impedances of canonical cases could be presented as special cases of Blackman's impedance relation."" (Abramovitz, Several Alternative Derivations of Blackman's Impedance Relation)‎