diff --git a/53_regression.Rmd b/53_regression.Rmd
index 40c2440..0fe44e9 100644
--- a/53_regression.Rmd
+++ b/53_regression.Rmd
@@ -7,7 +7,7 @@ John Fox and Sanford Weisberg, [_An R Companion to Applied Regression, Second Ed
 
 Gareth James, Daniela Witten, Trevor Hastie and Robert Tibshirani, _An Introduction to Statistical Learning: With Applications in R_, Springer (2013) [@James_Witten_Hastie_Tibshirani_2014]
 
-Paul Roback and Julie Legler, _Beyond Multiple Linear Regression: Applied Generalized Linear Models and Multilevel Models in R_, CRC Press, 2020 [@Roback_Legler_2020]
+Paul Roback and Julie Legler, _Beyond Multiple Linear Regression: Applied Generalized Linear Models and Multilevel Models in R_, CRC Press, 2021 [@Roback_Legler_2021]
 
 Jeremy Anglin, ["Using R to replicate common SPSS multiple regression output"](http://jeromyanglim.blogspot.ca/2013/12/using-r-to-replicate-common-spss.html) (2013-12-04)
 
diff --git a/book.bib b/book.bib
index 2185a6a..d24e994 100644
--- a/book.bib
+++ b/book.bib
@@ -551,11 +551,11 @@ @online{Ricks_pie_2020
 }
 
 
-@Book{Roback_Legler_2020,
+@Book{Roback_Legler_2021,
   title = {Beyond Multiple Linear Regression: Applied Generalized Linear Models and Multilevel Models in R},
   author = {Paul Roback, Julie Legler},
   publisher = {Chapman and Hall/CRC Press},
-  year = {2020},
+  year = {2021},
   isbn = {ISBN 9781439885383},
   url = {https://www.routledge.com/Beyond-Multiple-Linear-Regression-Applied-Generalized-Linear-Models-And/Roback-Legler/p/book/9781439885383}
 }