I finally found this book. The portion on Joseph Duckett is found on pg 198. It gives a statement that Joseph Duckett married 1788 in SC to Mary Turner with birth and death dates shown for each. There is no evidence or documents presented to show where the name Mary Turner or the dates were found. No indication of what records were checked or even a simple statement as to where the name or dates were found. In fact, the paragraph ends with this statement "He is believed to have married Dinah Smith. Do NOT know whether Dinah or Mary is correct?"
This deed, found in Newberry County SC Deed Book T-2, pp 307-309 , dated 3 Dec 1825 shows Dinah Duckett, Jacob Duckett, and William Duckett heirs and reps. of Joseph Duckett, deceased to Benjamin Duckett also heir, No mention of Mary Duckett.
Just wondering how this book can be used by so many as definitive proof that Joseph Duckett married Mary Turner?