Full Idea
The problem of restricted deductive power has haunted disquotational theories of truth (…because they can't prove generalisations).
Gist of Idea
Disquotational truth theories are short of deductive power
Source
Volker Halbach (Axiomatic Theories of Truth [2011], 19.5)
Book Reference
Halbach,Volker: 'Axiomatic Theories of Truth' [CUP 2011], p.280