update resources

Author: libjohn

README.md

@@ -15,12 +15,16 @@ The objective of this workshop is to introduce practical georeferencing (lat/lon
 
 - [Five great charts in 5 lines of R code each](https://www.r-bloggers.com/five-great-charts-in-5-lines-of-r-code-each/) by Sharon Maclis
 - [TidyCensus](https://walkerke.github.io/tidycensus/) by Kyle Walker
+- [`sf` package](https://r-spatial.github.io/sf/) -- Simple Features for R
+- [`mapview`](https://r-spatial.github.io/mapview/)
 - [Using tidycensus and leaflet to Map Census Data](https://juliasilge.com/blog/using-tidycensus/) by Julia Silge
+- [Geocomputation with R](https://geocompr.robinlovelace.net/) by Lovelace, Nowosad, Muenchow
+- [Converting XY Data with SF](https://ryanpeek.github.io/2017-08-03-converting-XY-data-with-sf-package/)
+- [Spatial Data Science](https://keen-swartz-3146c4.netlify.com/) by Pebesma & Bivand
 - Sharon Maclis - [Mapping in R just got a whole lot easier](https://www.computerworld.com/article/3175623/data-analytics/mapping-in-r-just-got-a-whole-lot-easier.html)
 - [Introduction to Spatial Data Types in R](https://cengel.github.io/rspatial/2_spDataTypes.nb.html#how-to-do-this-in-sf) by Claudia Engel
 - DataCamp.com's [Working with Geospatial Data in R](https://www.datacamp.com/courses/working-with-geospatial-data-in-r) by Charlotte Wickham
 - [Introduction to visualising spatial data in R](https://cran.r-project.org/doc/contrib/intro-spatial-rl.pdf). Lovelace, Cheshire, and Oldroyd
-- [Simple Features for R](https://r-spatial.github.io/sf/index.html)
 - [tmap in a nutshell](https://cran.r-project.org/web/packages/tmap/vignettes/tmap-nutshell.html)
 - [viridis color palettes](https://cran.r-project.org/web/packages/viridis/vignettes/intro-to-viridis.html)