The problem is here: 
'Programming' => { q/Expert's Guide to Scala/ },

[download]
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

In reply to Re: A "simple" question regarding accessing a value in a complex data structure. by choroba
in thread A "simple" question regarding accessing a value in a complex data structure. by Anonymous Monk

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