<s>
The	O
Book	B-Library
Citation	I-Library
Index	I-Library
(	O
BCI	O
,	O
BKCI	O
)	O
is	O
an	O
online	O
subscription-based	O
scientific	O
citation	O
indexing	O
service	O
maintained	O
by	O
Clarivate	O
Analytics	O
and	O
is	O
part	O
of	O
the	O
Web	B-Library
of	I-Library
Science	I-Library
Core	I-Library
Collection	I-Library
.	O
</s>
<s>
In	O
their	O
2014	O
book	O
Beyond	O
Bibliometrics	O
:	O
Harnessing	O
Multidimensional	O
Indicators	O
of	O
Scholarly	O
Impact	O
,	O
Blaise	O
Cronin	O
and	O
Cassidy	O
R	O
.	O
Sugimoto	O
noted	O
that	O
"	O
for	O
impact	O
assessment	O
of	O
book-based	O
fields	O
,	O
bibliometricians	O
need	O
a	O
database	O
with	O
large	O
numbers	O
of	O
books	O
"	O
and	O
that	O
while	O
the	O
Book	B-Library
Citation	I-Library
Index	I-Library
did	O
meet	O
this	O
need	O
,	O
Google	B-Application
Books	I-Application
also	O
fulfilled	O
this	O
purpose	O
and	O
was	O
not	O
only	O
free	O
,	O
but	O
was	O
(	O
at	O
the	O
time	O
)	O
more	O
comprehensive	O
for	O
bibliometric	O
analyses	O
.	O
</s>
<s>
They	O
also	O
stated	O
that	O
the	O
Book	B-Library
Citation	I-Library
Index	I-Library
was	O
"	O
a	O
first	O
step	O
toward	O
creating	O
a	O
reliable	O
and	O
necessary	O
citation	O
data	O
source	O
for	O
monographs	O
—	O
a	O
very	O
challenging	O
issue	O
,	O
because	O
,	O
unlike	O
journals	O
and	O
conference	O
proceedings	O
,	O
books	O
have	O
specific	O
requirements	O
,	O
and	O
several	O
problems	O
emerge	O
not	O
only	O
in	O
the	O
context	O
of	O
subject	O
classification	O
,	O
but	O
also	O
in	O
their	O
role	O
as	O
cited	O
publications	O
and	O
in	O
citing	O
publications.	O
"	O
</s>
