The 'Author's Effect of Showcasing' (AES) is the activity of publishing authors with which they shape by their own free will the formal reference stock of their communications, placing this stock into the showcase of science. This paper reports the results of a decisive control test of the existence of the AES, processing 1175 historically synchronous physics conference communications. Applying methods of bibliometrics and science philology, the manifestation of the AES phenomenon is demonstrated and analyzed in this theoretically most homogeneous domain of scientific literature. The widely differing documentedness in the communications of conferences held on particular topics of physics, especially the great differences in the size of the formal reference stocks in all extent categories of the communications depends solely on the person of the authors. This generally and extremely heterogeneous documentedness is therefore a valid evidence of the existence of the effect and its effective operation in the scientific literature. The correctness of the AES doctrine, including the correctness of two additional theses, has been demonstrated: the relatively diminishing growth of the formal reference stock and specific documentedness with the growth in the extend of communications, and the existence of weakly, moderately, strongly and very strongly documented communications in all extent categories of the communications.