Book: Larsen, Ellouise Baker. 1974 American Historical Views on Staffordshire China.
• See pg 31 for pattern description.Electronic: Transferware Collectors Club. Transferware Collectors Club Database of Patterns & Sources. Transferware Collectors Club 03/13/2024 https://www.transferwarecollectorsclub.org/members/database
• Wood factory "Union Line" pattern: pattern title listed as Union Line (alternate name: Shell border Series Irregular or Grotto-Shaped Center), pattern no. 2001. Border pattern identified as Shell Border, Irregular or Grotto-Shaped Center: Enoch Wood & Sons. Enoch Wood & Sons factory, Burslem, Staffordshire, 1818-46, with impressed Bird-type maker's mark.