Reference--Robert Charles Anderson, The Great Migration Directory: Immigrants to New England, 1620–1640: A Concise Compendium (Boston, Massachusetts : New England Historic Genealogical Society, 2015).
Lawrence's brother was received at Salem, 23 January 1635/7. For this claim, Anderson cites "STR 1:33." See Robert Charles Anderson, The Great Migration Begins: Immigrants to New England 1620-1633, Volumes I-III, 3 vols. (Boston: New England Historic Genealogical Society, 1995), 2:1161-1164 (Lawrence Leach) at 1163 (Associations); digital images by subscription, AmericanAncestors.