<s>
A	O
bibliographic	B-Library
database	I-Library
is	O
a	O
database	O
of	O
bibliographic	B-Library
records	I-Library
,	O
an	O
organized	O
digital	O
collection	O
of	O
references	O
to	O
published	O
literature	O
,	O
including	O
journal	O
and	O
newspaper	O
articles	O
,	O
conference	O
proceedings	O
,	O
reports	O
,	O
government	O
and	O
legal	O
publications	O
,	O
patents	O
,	O
books	O
,	O
etc	O
.	O
</s>
<s>
In	O
contrast	O
to	O
library	B-Library
catalogue	I-Library
entries	O
,	O
a	O
large	O
proportion	O
of	O
the	O
bibliographic	B-Library
records	I-Library
in	O
bibliographic	B-Library
databases	I-Library
describe	O
articles	O
,	O
conference	O
papers	O
,	O
etc.	O
,	O
rather	O
than	O
complete	O
monographs	O
,	O
and	O
they	O
generally	O
contain	O
very	O
rich	O
subject	O
descriptions	O
in	O
the	O
form	O
of	O
keywords	O
,	O
subject	O
classification	O
terms	O
,	O
or	O
abstracts	O
.	O
</s>
<s>
A	O
bibliographic	B-Library
database	I-Library
may	O
be	O
general	O
in	O
scope	O
or	O
cover	O
a	O
specific	O
academic	O
discipline	O
like	O
computer	B-General_Concept
science	I-General_Concept
.	O
</s>
<s>
A	O
significant	O
number	O
of	O
bibliographic	B-Library
databases	I-Library
are	O
proprietary	O
,	O
available	O
by	O
licensing	O
agreement	O
from	O
vendors	O
,	O
or	O
directly	O
from	O
the	O
indexing	B-Library
and	I-Library
abstracting	I-Library
services	I-Library
that	O
create	O
them	O
.	O
</s>
<s>
Many	O
bibliographic	B-Library
databases	I-Library
have	O
evolved	O
into	O
digital	O
libraries	O
,	O
providing	O
the	O
full	O
text	O
of	O
the	O
indexed	O
contents	O
:	O
for	O
instance	O
CORE	B-Algorithm
also	O
mirrors	O
and	O
indexes	O
the	O
full	O
text	O
of	O
scholarly	O
articles	O
and	O
Our	O
Research	O
develops	O
a	O
search	B-Application
engine	I-Application
for	O
open	O
access	O
content	O
found	O
by	O
Unpaywall	O
.	O
</s>
<s>
Others	O
converge	O
with	O
non-bibliographic	O
scholarly	O
databases	O
to	O
create	O
more	O
complete	O
disciplinary	O
search	B-Application
engine	I-Application
systems	O
,	O
such	O
as	O
Chemical	O
Abstracts	O
or	O
Entrez	O
.	O
</s>
<s>
Prior	O
to	O
the	O
mid-20th	O
century	O
,	O
individuals	O
searching	O
for	O
published	O
literature	O
had	O
to	O
rely	O
on	O
printed	O
bibliographic	B-Library
indexes	I-Library
,	O
generated	O
manually	O
from	O
index	O
cards	O
.	O
</s>
<s>
These	O
databases	O
contained	O
bibliographic	O
descriptions	O
of	O
journal	O
articles	O
that	O
were	O
searchable	B-Application
by	O
keywords	O
in	O
author	O
and	O
title	O
,	O
and	O
sometimes	O
by	O
journal	O
name	O
or	O
subject	O
heading	O
.	O
</s>
