Thank you for posting page 29.
The original source that referenced "page 29" in Parker and Dubberstein was an 1968 article published in The Watchtower (see below).
I do not see why The Watchtower gave the specific page number reference.
w68 8/15 pp. 493-494 par. 23 The Book of Truthful Historical Dates
He issued the famous edict permitting the Jews to return and rebuild Jehovah’s temple, copies of which were written and circulated throughout the realm. This allowed sufficient time for the Jews to resettle in their homeland, ‘establish the altar firmly upon its own site,’ and “from the first day of the seventh month” start offering up burnt sacrifices to Jehovah. This date, the “first day of the seventh month,” according to the best astronomical tables available (Brown University Studies, Vol. XIX, Babylonian Chronology 626 B.C.—A.D. 75, (1956) Parker and Dubberstein, p. 29), is calculated to be October 5 (Julian) or September 29 (Gregorian) 537 B.C.E.—Ezra 1:1-4; 3:1-6.