Book: Webster, Donald Blake. 1971 Decorated Stoneware Pottery of North America.
• Published: p. 186, no. 255, suggests possibly a clockface (but more likely a sundial)).Book: Sandon, John. 1993 The Dictionary of Worcester Porcelain, 1751-1851, Volume 1. 1.
• Worcester porcelain sundial made for senior partner Josiah Holdship, dated 1766.Catalogue: Crocker Farm, Inc. Crocker Farm Auction Catalogue.
• Similar sundial differing in script "H.C. Bailey" inscription: July, 20, 2019 sale, lot 24, attributed to Richard C. Remmey, Philadelphia, c. 1885Article: Leder, Steven B. 01//1985 A Stoneware Sundial. Stoneware Collectors Journal. 2 (1): 21-23.