Book: Godden, Geoffrey A. 1991 Encyclopaedia of British Pottery and Porcelain Marks.
• Crown over "BFB": p. 695, no. 4339 "Standard impressed mark found on all wares, with or without written or printed marks, c. 1807-13."Book: Sandon, John. 1993 The Dictionary of Worcester Porcelain, 1751-1851, Volume 1. 1.
• Similar form sugar or (mdern) "sugar boat," c. 1810: p. 322, "From 1800-7 Flight's factory made open sugar bowls [of] oval section...They never came with covers..."