AE - Encyclopedias 3,508
AC - Collections and Collected Works 64
AZ - History of Scholarship 48
AG - Dictionaries and Reference 36
AS - Academies 31
AM - Museums and Collecting 27
AY - Yearbooks, Almanacs, Directories 11
PS - American Literature 6
AI - Indexes 5
PR - English Literature 5
AP - Periodicals 3
B - Philosophy 3
C - General History 3
F - General American History 3
LD - United States 2
PQ - French, Italian, Spanish, Portuguese Literature 2
S - General Agriculture 2
BS - The Bible 1
BX - Christian Denominations 1
E - United States History 1
HA - Statistics 1
HE - Transportation and Communications 1
LC - Social Aspects of Education 1
PA - Latin and Greek 1
PG - Slavic, Baltic, Abanian Languages 1
QE - Geology 1
QR - Microbiology 1
TA - General and Civil Engineering 1