more content, fix some typos and formating

40_data_visualization.Rmd

@@ -18,7 +18,7 @@ But start here:
 
 * Elijah Meeks, ["What Charts Do"](https://medium.com/@Elijah_Meeks/what-charts-do-48ed96f70a74) (2018-05-21) is a succinct summary that's worth reading.
 
-* Cole Nussbaumer Knaflic, [_Storytelling with Data_] [@NussbaumerKnaflic_2015]. A great introduction to the fundamentals of good visualization. The [companion blog](https://www.storytellingwithdata.com/) has is an on-going series of further dives into the topic.
+* Cole Nussbaumer Knaflic, _Storytelling with Data_ [@NussbaumerKnaflic_2015]. A great introduction to the fundamentals of good visualization. The [companion blog](https://www.storytellingwithdata.com/) has an on-going series of further dives into the topic.
 
 * Naomi Robbins, _Creating More Effective Graphs_. [@Robbins_2013]
 
@@ -50,6 +50,10 @@ Design Space of Data Visualization"](https://www.sciencedirect.com/science/artic
 
     - background: ["Multiple views on how to choose a visualization"](https://medium.com/multiple-views-visualization-research-explained/multiple-views-on-how-to-choose-a-visualization-b3ffc99fcddc), 2019-04-24, at medium.com
 
+
+* Michael Friendly, [DataVis.ca](http://datavis.ca/) -- a variety of resources, including the "Milestones Project" (significant events in the history of data visualization), books, courses, papers, and R materials.
+
+
 * Kieran Healy _Data Visualization: A practical introduction_. [@Healy_2019]
 
     - [online version](http://socviz.co/)
@@ -91,6 +95,8 @@ Design Space of Data Visualization"](https://www.sciencedirect.com/science/artic
 
 * [R Graph Catalog](http://shiny.stat.ubc.ca/r-graph-catalog/) -- an unbeatable resource for making good graphs in R, described by the creators as "a complement to _Creating More Effective Graphs_ by Naomi Robbins."  [@Robbins_2013]
 
+* Michael Friendly and David Meyer (2016) _Discrete Data Analysis with R_ [@Friendly_Meyer_2016]
+
 * Kieran Healy _Data Visualization: A practical introduction_. [@Healy_2019]
 
     - [online version](http://socviz.co/)
@@ -121,7 +127,7 @@ Design Space of Data Visualization"](https://www.sciencedirect.com/science/artic
 
 ### extensions
 
-**ggplot2** extensions, catalogued at [www.ggplot2-exts.org](https://www.ggplot2-exts.org/index.html)
+There are many extension packages that allow you to make other visualizations in **ggplot2**. Some are catalogued at [www.ggplot2-exts.org](https://www.ggplot2-exts.org/index.html).
 
 * Gallery of **ggplot2** extensions: [ggplot2-exts.org/gallery/](ggplot2 extensions - gallery )
 
@@ -135,7 +141,6 @@ Design Space of Data Visualization"](https://www.sciencedirect.com/science/artic
 
 ** _Note:_**
 
-There are many extension packages that allow you to make other visualizaitons in **ggplot2**; they are referenced below.
 
 
 ### Plotly

book.bib

@@ -102,6 +102,17 @@ @article{tm
 
 
 
+@Book{Friendly_Meyer_2016,
+  title = {Discrete Data Analysis with R: Visualization and Modeling Techniques for Categorical and Count Data},
+  author = {Michael Friendly and
+            David Meyer},
+  publisher = {CRC Press},
+  year = {2016},
+  isbn = {ISBN 978-1-4987-2583-5},
+}
+
+
+
 @Book{Gelman_etal_2014,
   title = {Bayesian Data Analysis (Third Edition)},
   author = {Andrew Gelman, John B. Carlin,

index.Rmd

@@ -39,10 +39,10 @@ The source code for this ebook can be found at this github repository: https://g
 
 **Cover image**
 
-For the cover, I wanted to use a photo of the Main Hall of the old Cincinnati Library, which one can find all over the internet. But going to source, I see that it's _not_ offered by the Public Library of Cincinnati under an open license. But you can follow [this link and see it there](https://www.flickr.com/photos/cincinnatipubliclibrary/3357891281).
+For the cover, I wanted to use a photo of the Main Hall of the old Cincinnati Library, which one can find all over the internet. But going to the source, I see that it's _not_ offered by the Public Library of Cincinnati under an open license. But you can follow [this link and see it there](https://www.flickr.com/photos/cincinnatipubliclibrary/3357891281).
 
 
-This book is written in **Markdown**, using the **bookdown** package.
+This book is written in **Markdown**, using the [**bookdown**](https://bookdown.org/yihui/bookdown/) package, and published to the web at [bookdown.org](https://bookdown.org/).
 
 
 ```{r eval=FALSE}