<s>
In	O
legal	O
research	O
,	O
a	O
citator	B-Library
is	O
a	O
citation	O
index	O
of	O
legal	O
resources	O
,	O
one	O
of	O
the	O
best-known	O
of	O
which	O
in	O
the	O
United	O
States	O
is	O
Shepard	B-Library
's	I-Library
Citations	I-Library
.	O
</s>
<s>
Given	O
a	O
reference	O
of	O
a	O
legal	O
decision	O
,	O
a	O
citator	B-Library
allows	O
the	O
researcher	O
to	O
find	O
newer	O
documents	O
which	O
cite	O
the	O
original	O
document	O
and	O
thus	O
to	O
reconstruct	O
the	O
judicial	O
history	O
of	O
cases	O
and	O
statutes	O
.	O
</s>
<s>
Using	O
a	O
citator	B-Library
in	O
this	O
way	O
is	O
colloquially	O
referred	O
to	O
as	O
"	O
Shepardizing	B-Library
"	O
.	O
</s>
<s>
Because	O
cases	O
cite	O
related	O
cases	O
,	O
citators	B-Library
can	O
be	O
used	O
to	O
find	O
cases	O
which	O
are	O
on	O
topics	O
related	O
to	O
a	O
given	O
topic	O
.	O
</s>
<s>
Citators	B-Library
often	O
include	O
annotations	O
indicating	O
the	O
history	O
and	O
treatment	O
of	O
a	O
case	O
in	O
citing	O
opinions	O
.	O
</s>
<s>
Although	O
originally	O
distributed	O
only	O
as	O
printed	O
and	O
bound	O
volumes	O
,	O
citators	B-Library
are	O
now	O
typically	O
on-line	O
services	O
such	O
as	O
LexisNexis	B-Library
's	O
online	O
Shepard	B-Library
's	I-Library
Citations	I-Library
,	O
Justis	O
Publishing	O
's	O
provider-neutral	O
JustCite	O
,	O
Westlaw	O
's	O
KeyCite	O
,	O
Bloomberg	O
Law	O
's	O
BCite	O
,	O
and	O
the	O
Oxford	O
Law	B-Library
Citator	I-Library
of	O
Oxford	O
University	O
Press	O
.	O
</s>
<s>
But	O
the	O
most	O
important	O
and	O
best-known	O
citation	O
index	O
came	O
with	O
the	O
1873	O
publication	O
of	O
Shepard	B-Library
's	I-Library
Citations	I-Library
.	O
</s>
<s>
Frank	O
Shepard	O
Company	O
started	O
publishing	O
citators	B-Library
in	O
New	O
York	O
City	O
in	O
1873	O
and	O
other	O
companies	O
provided	O
similar	O
services	O
at	O
around	O
the	O
same	O
time	O
,	O
e.g.	O
</s>
<s>
The	O
name	O
'	O
citator	B-Library
 '	O
appears	O
to	O
have	O
been	O
coined	O
by	O
the	O
Citator	B-Library
Publishing	O
Company	O
(	O
Detroit	O
)	O
in	O
1908	O
in	O
The	O
Citator	B-Library
:	O
an	O
annotated	O
compilation	O
of	O
citations	O
of	O
the	O
Kansas	O
Supreme	O
Court	O
....	O
</s>
