The category "<n-not_proper_name-unit>" can be expressed as follows:

<n-not_proper_name-unit>

<n-not_mod-kind> of <n-not_mod-not_proper_name-unit>

<n-not_mod-sing-kind> of <n-not_mod-not_proper_name-unit>

<unit_nom>

<unit_nom-sing>