diff --git a/03-survey-data-documentation.Rmd b/03-survey-data-documentation.Rmd
index 6fe36925..f58a2586 100644
--- a/03-survey-data-documentation.Rmd
+++ b/03-survey-data-documentation.Rmd
@@ -94,7 +94,7 @@ Some observations in a dataset may have missing data. This can be due to design
 
 The survey documentation, often the codebook, represents the missing data with a code. The codebook may list different codes depending on why certain data points are missing. In the example of variable `V202066` from the ANES (Figure \@ref(fig:understand-codebook-examp)), `-9` represents "Refused," `-7` means that the response was deleted due to an incomplete interview, `-6` means that there is no response because there was no follow-up interview, and `-1` means "Inapplicable" (due to a designed skip pattern.) 
 
-As another example, there may be a summary variable that describes the missingness of a set of variables - particularly with "select all that apply" or "multiple response" questions. In the National Crime Victimization Survey (NCVS), respondents who are victims of a crime and saw the offender are asked if the offender had a weapon and then asked what the type of weapon was. This part of the questionnaire from 2021 is shown in Figure \@ref(fig:understand-ncvs-weapon-q).
+As another example, there may be a summary variable that describes the missingness of a set of variables - particularly with "select all that apply" or "multiple response" questions. In the National Crime Victimization Survey (NCVS), respondents who are victims of a crime and saw the offender are asked if the offender had a weapon and then asked what the type of weapon was. This part of the questionnaire from 2021 is shown in Figure \@ref(fig:understand-ncvs-weapon-q) [@ncvs_survey_2020].
 
 ```{r}
 #| label: understand-ncvs-weapon-q
@@ -105,7 +105,7 @@ As another example, there may be a summary variable that describes the missingne
 knitr::include_graphics(path="images/questionnaire-ncvs-weapon.jpg")
 ```
 
-The NCVS codebook includes coding for all multiple response variables of a "lead in" variable that summarizes the individual options. For question 23a on the weapon type, the lead-in variable is V4050, which is shown in \@ref(fig:understand-ncvs-weapon-cb). This variable is then followed by a set of variables for each weapon type. An example of one of the individual variables from the codebook, the handgun, is shown in \@ref(fig:understand-ncvs-weapon-cb-hg). We will dive into how to analyze this variable in Chapter \@ref(c11-missing-data).
+The NCVS codebook includes coding for all multiple response variables of a "lead in" variable that summarizes the individual options. For question 23a on the weapon type, the lead-in variable is V4050, which is shown in Figure \@ref(fig:understand-ncvs-weapon-cb) [@ncvs_cb_2020]. This variable is then followed by a set of variables for each weapon type. An example of one of the individual variables from the codebook, the handgun, is shown in Figure \@ref(fig:understand-ncvs-weapon-cb-hg) [@ncvs_cb_2020]. We will dive into how to analyze this variable in Chapter \@ref(c11-missing-data).
 
 ```{r}
 #| label: understand-ncvs-weapon-cb
diff --git a/book.bib b/book.bib
index a466ba30..bc9eae34 100644
--- a/book.bib
+++ b/book.bib
@@ -111,7 +111,7 @@ @book{deming1991sample
 }
 @misc{ncvs_data_2021,
 	title        = {National {Crime} {Victimization} {Survey}, [{United} {States}], 2021},
-	author       = {{United States. Bureau of Justice Statistics}},
+	author       = {{U.S. Bureau of Justice Statistics}},
 	year         = 2022,
 	publisher    = {Inter-university Consortium for Political and Social Research [distributor]},
 	doi          = {10.3886/ICPSR38429.v1},
@@ -122,16 +122,29 @@ @misc{ncvs_user_guide
 	title        = {Users' guide to the {National} {Crime} {Victimization} {Survey} ({NCVS}) direct variance estimation},
 	author       = {{Shook-Sa, Bonnie} and {Couzens, G. Lance} and {Berzofsky, Marcus}},
 	year         = 2015,
-	publisher    = {Bureau of Justice Statistics},
+	publisher    = {U. S. Bureau of Justice Statistics},
 	howpublished = {\url{https://bjs.ojp.gov/sites/g/files/xyckuh236/files/media/document/ncvs_variance_user_guide_11.06.14.pdf}}
 }
 @misc{ncvs_tech_2016,
 	title        = {National {Crime} {Victimization} {Survey}, 2016: {Technical} {Documentation}},
-	author       = {{Bureau of Justice Statistics}},
+	author       = {{U. S. Bureau of Justice Statistics}},
 	year         = 2017,
 	month        = dec,
 	howpublished = {\url{https://bjs.ojp.gov/sites/g/files/xyckuh236/files/media/document/ncvstd16.pdf}}
 }
+@misc{ncvs_survey_2020,
+	title        = {National {Crime} {Victimization} {Survey} NCVS-2 CRIME INCIDENT REPORT},
+	author       = {{U. S. Bureau of Justice Statistics}},
+	year         = 2020,
+	howpublished = {\url{https://bjs.ojp.gov/content/pub/pdf/ncvs20_cir.pdf}}
+}
+@misc{ncvs_cb_2020,
+	title        = {{National Crime Victimization Survey}, [{United States}], 2021},
+	author       = {{U. S. Bureau of Justice Statistics}},
+	year         = 2022,
+	howpublished = {\url{https://www.icpsr.umich.edu/web/NACJD/studies/38429/datadocumentation}},
+	note         = {Download - DS0 Study-Level Files - Codebook [{PDF}]}
+}
 @article{gelman2007weights,
 	title        = {{Struggles with Survey Weighting and Regression Modeling}},
 	author       = {Andrew Gelman},