Source reference: 

Pugliese (2001)

Silvia Pugliese (2001), “Stiff-Board Vellum Binding with Slotted Spine”, Papier Restaurierung, Mitteilingen Der IADA 2 (Jahrbuch / supplement), pp. 93–101.

Additional reference: 
Entry for 'cartonnage', p. 589

Pickwoad, Onward and Downward... (1994)

Nicholas Pickwoad (1994), “Onward and Downward: How Binders Coped with the Printing Press before 1800”, in A Millennium of the Book: Production, Design and Illustration in Manuscript and Print 900-1900, edited by Michael Harris and Robin Myers, Publishing Pathways 8, Winchester, St. Paul’s Bibliographies, pp. 61–106.

Additional reference: 
p. 88

Used as preferred label for