Links not working

A previous topic on this same subject is no longer visible, so I’ll ask on my own behalf.

Several places in this book have text that appear to be web links, but as I’m reading the PDF version in macOS Preview, they do not respond to clicks. For example, page 57 near the bottom are apparent links “developer documentation” and “free tutorial”, both inert.

Is there some place in the RW web site where these links can be accessed?

I’m not sure why the links don’t render, but here they are:

developer documentation: Writing Test Classes and Methods

free tutorial:

Thanks! It’s curious that these links are failing, as other links in the same book work as expected. (I’m using Preview 10.0 under macOS 10.13.6 (High Sierra) to read the PDF version of the book.)