= 20 Book Rarities.=
21 Manuscripts.
22 Block Books.
23 Early Printed.
24 Celebrated Printers.
25 Celebrated Binders.
26 Materials.
27 Ownership.
28 Prohibited.
29 Other.

= 30 General Cyclopedias.=
31 American.
32 English.
33 German.
34 French.
35 Italian.
36 Spanish.
37 Slavic.
38 Scandinavian.
39 Other.

= 40 Polygraphy.=
41 American.
42 English.
43 German.
44 French.
45 Italian.
46 Spanish.
47 Slavic.