Use ?attr in string-array

I have this kind of array under arrays.xml :

<string-array name="menu_icons">
        <item>?attr/book_icon</item>
        <item>?attr/book_icon</item>
        <item>?attr/book_icon</item>
        <item>?attr/book_icon</item>
        <item>?attr/book_icon</item>
        <item>?attr/book_icon</item>
    </string-array>

Under styles.xml :

<attr name="book_icon" format="reference" />

But how can I retrieve this from Java code ?

I have try this :

TypedArray icons = context.getResources().obtainTypedArray(R.array.menu_icons);
icons.getDrawable(i);//Crash Resource is not a Drawable (color or path): TypedValue
icons.getRessourceId(i, -1);//Crash Resource is not a Drawable (color or path): TypedValue