Further reading and a typo fix for debugging lecture

lectures/debugging-strategies/slides.qmd

@@ -438,7 +438,7 @@ In the Fortran world, also
 
 Try with more than just one compiler
 
-$\Rightarrow$ HPC systems usally provide native compiler plus gcc/gfortan. Try both variants.
+$\Rightarrow$ HPC systems usually provide native compiler plus gcc/gfortan. Try both variants.
 
 
 
@@ -878,3 +878,6 @@ end program loop_count_2d
 ::::::::
 
 
+# Further reading
+
+Topic 20 (in ch 3) of *The pragmatic programmer* [UHH Library system](https://katalogplus.sub.uni-hamburg.de/vufind/Record/168729271X) | [MPS ebooks](https://ebooks.mpdl.mpg.de/ebooks/Record/EB001950880) | [German ebook via UHH](https://katalogplus.sub.uni-hamburg.de/vufind/Record/1755846843)