"Role of Scots in Economy of West Indies" at slavery conference in NYC, 1976; "In Search of the Plantation History of the British West Indies," "Medical and Demographic Aspects of Slavery in the British Caribbean Colonies, 1689-1835," in Seattle, 1984; "The West India Sugar Crisis and British Slave Emancipations, 1830-1833," 1961; "Samuel Martin, Innovating Sugar Planter of Antigua, 1750-1776," 1960; "The Commercial and Financial Organization of the British Slave Trade, 1750-1807," 1958; and "The British Credit Crisis of 1772 and the American Colonies," 1960.