see if this helps:
the last few paragraphs of the article in the above link reads:
For example, as mentioned above on pages 15 and 96, the Adda-Guppi stele mentions the reign of every Neo-Babylonian king except Labashi-Marduk, down into the reign of Nabonidus, in which the queen died. There are also the Hillah stele, Nabonidus No. 8, and another designated Nabonidus No. 18 (see
). <<<< click on this link too)
In summary, the paragraph establishes a standard of absolute completeness and perfection, and then claims that since this unattainable standard has not been met, the evidence is no good. This is yet another straw man. An attempt is made to mislead the reader into believing there is no contemporary historical evidence, but archeological discoveries show this is wrong.
The third paragraph on astronomical evidence, about factors "greatly reducing its strength," degenerates into pure speculation and is totally without content.
In this appendix we have examined the various evidences the Watchtower Society has used over the years to support the 539 B.C. date for the fall of Babylon. We have seen that until very recent times the Society relied exclusively on the word of "recognized authorities" to establish the date, and that it is still forced to do so with respect to astronomical dating, lunar eclipses and cuneiform business tablets. Yet the Society rejects all these historical evidences when they conflict with its date of 607 B.C. for the destruction of Jerusalem. As Edwin Thiele said, the way the Society discusses chronology "reminds me of the way an unscrupulous lawyer would deal with facts in order to support a case he knows not to be sound."