Book: Gilhepsy, F. Brayshaw. 1961 Derby Porcelain.
• "Smith's Blue" discussed: p. 103 and illustrated: plate II.Catalogue: Bonhams (auction catalogue).
• Very similar mug: September 9, 2009 (London), lot 257, Chelsea-Derby mug painted in style of Edward Withers with "Smith's blue" and gold border, 1770-77, and blue crown over D mark.