BYU Research concludes Joseph Smith Copied a 1831 Bible Book to create the JST of the Bible.
A BYU Research Paper published in March 2017 exposes parallels between the Joseph Smith Translation of the Bible, and a book published in 1831, called Adam Clark's Holy Bible Commentary, available here.
The BYU report reads:
"... recently, in conducting new research into the origins of Smith’s Bible translation, we uncovered evidence that Smith and his associates used a readily available Bible commentary while compiling a new Bible translation, or more properly a revision of the King James Bible. The commentary, Adam Clarke’s famous Holy Bible, Containing the Old and New Testaments, was a mainstay for Methodist theologians and biblical scholars alike, and was one of the most widely available commentaries in the mid-1820s and 1830s in America." and "Our research has revealed that the number of direct parallels between Smith’s translation and Adam Clarke’s biblical commentary are simply too numerous and explicit to posit happenstance or coincidental overlap."
Information about Adam Clarke:
Adam Clarke (1760 or 1762-1832) was a British Methodist theologian and Biblical scholar. He is primarily remembered for writing this commentary on the Bible. It took him 40 years to complete this work. Clarke adhered theologically to the Methodist founder John Wesley. Clarke's commentary is largely written from an orthodox Methodist perspective.