The first publisher of UBKh Apollo Skalkovsky treated it with great enthusiasm.
Javornytsky was right in comparing the text of UBKh with Grabianka's work, to say he was in one step from discovery – that Grabianka was source of UBKh. But he was not done this step. This step and the glory of discovety belong to next author – Andrew Storozhenko.
Andrew Storozhenko devoted a separate chapter of his book to UBkh. There he wrote:
One can not have any doubt in falsification of diploma and the universal that contain it [Storozhenko A. V. Stephen Báthory and the Dnieper Cossacks. – Moscow, 1904, p. 141 – 142].
It is an abstract of the chapter. For the full text see please ukrainian version.