diff --git a/vignettes/OTPv2.Rmd b/vignettes/OTPv2.Rmd
index 3da249c..626b1d8 100644
--- a/vignettes/OTPv2.Rmd
+++ b/vignettes/OTPv2.Rmd
@@ -40,9 +40,9 @@ It is possible to install multiple version of Java on the same computer:
 
 **Download Links**
 
-* [Java 8](https://www.java.com/en/download/manual.jsp)
-* [Java 11](https://www.oracle.com/java/technologies/javase-jdk11-downloads.html)
-* [Java 17](https://www.oracle.com/java/technologies/downloads/#java17)
+* [Java 8](https://www.java.com/en/download/)
+* [Java 11](https://www.oracle.com/uk/java/technologies/javase/jdk11-archive-downloads.html)
+* [Java 17](https://www.oracle.com/java/technologies/javase/jdk17-archive-downloads.html)
 
 If you have multiple version of Java installed you will also need to change the PATH variable to point to the correct version of Java. You can check your current default version of Java in the terminal using
 
diff --git a/vignettes/opentripplanner.Rmd b/vignettes/opentripplanner.Rmd
index 41cd0c4..20db0f6 100644
--- a/vignettes/opentripplanner.Rmd
+++ b/vignettes/opentripplanner.Rmd
@@ -233,7 +233,7 @@ OTP can use public transport timetable data in the [GTFS format](https://develop
 
 #### Elevation Data
 
-You can add terrain information to your routes, especially useful for walking and cycling, using [GeoTIFF images](https://trac.osgeo.org/geotiff). You can find worldwide elevation data from [NASA](https://www2.jpl.nasa.gov/srtm/).
+You can add terrain information to your routes, especially useful for walking and cycling, using [GeoTIFF images](https://trac.osgeo.org/geotiff). You can find worldwide elevation data from [NASA](https://www.usgs.gov/centers/eros/science/usgs-eros-archive-digital-elevation-shuttle-radar-topography-mission-srtm-non#overview).
 
 **Warning** It is common for GeoTIFF to have a no data value often the maximum possible value. OTP can misinterpret this as an elevation value. So set your no data values in your elevation data to something more plausible like 0.
 
diff --git a/vignettes/prerequisites.Rmd b/vignettes/prerequisites.Rmd
index db48cbc..43e6a23 100644
--- a/vignettes/prerequisites.Rmd
+++ b/vignettes/prerequisites.Rmd
@@ -25,7 +25,7 @@ This package allows you to use the trip planning power of OTP with the analytica
 
 The `opentripplanner` R package makes it easier for R and OpenTripPlanner to communicate.
 Specifically, it allows you to do use R to control OTP and use it as a local routing service.
-For more on local versus remote routing services, see the Transportation chapter in [Geocomputation with R](https://geocompr.robinlovelace.net/transport.html).
+For more on local versus remote routing services, see the Transportation chapter in [Geocomputation with R](https://r.geocompx.org/transport.html).
 
 ### What are R and RStudio?
 
@@ -37,7 +37,7 @@ An R package is a small piece of software that extends the basic capabilities of
 
 ### Help with R
 
-To get started with R, see [An Introduction to R](https://cran.r-project.org/doc/manuals/r-release/R-intro.pdf) or from within R by running `help.start()`, introductory tutorials such as DataCamp's free Introduction to R course, or the [R tutor website](https://www.r-tutor.com/r-introduction). The [Geocomputation with R](https://geocompr.robinlovelace.net) book covers the packages and skills required to analyse spatial datasets such as those produced by OpenTripPlanner.
+To get started with R, see [An Introduction to R](https://cran.r-project.org/doc/manuals/r-release/R-intro.pdf) or from within R by running `help.start()`, introductory tutorials such as DataCamp's free Introduction to R course, or the [R tutor website](https://www.r-tutor.com/r-introduction). The [Geocomputation with R](https://r.geocompx.org/) book covers the packages and skills required to analyse spatial datasets such as those produced by OpenTripPlanner.
 
 A video tutorial for installing R and RStudio 
 
@@ -103,7 +103,7 @@ The package includes a simple function for checking if you have the correct vers
 
 To get Java:
 
-* **Windows/Mac** https://www.java.com/en/download/ This link defaults to the 32 Bit version, so also check https://java.com/en/download/manual.jsp.
+* **Windows/Mac** https://www.java.com/en/download/ This link defaults to the 32 Bit version, so also check https://www.java.com/en/download/help/java_win64bit.html.
 
 * **Linux**  we recommend instructions at [StackOverflow](https://askubuntu.com/questions/740757/switch-between-multiple-java-versions).