in reply to A "simple" question regarding accessing a value in a complex data structure.

The problem is here:
'Programming' => { q/Expert's Guide to Scala/ },
Curly brackets introduce an anonymous hash, but there is only one element inside: q/Expert's Guide to Scala/. Remove the curlies.
لսႽ† ᥲᥒ⚪⟊Ⴙᘓᖇ Ꮅᘓᖇ⎱ Ⴙᥲ𝇋ƙᘓᖇ