Art as communication, by L. Tolstoi.
Art, intuition, and expression, by B. Groce.
Art as expression, by R. G. Collingwood.
The Groce-Collingwood theory of art, by J. Hospers.
The act of expression, by J. Dewey.
Art and the language of the emotions, by C. J. Ducasse.
Music as impressive and music as expressive, by E. Gurney.
Expression, by G. Santayana.
The expressiveness of colors, by W. Kadinsky.
Expression and association, by C. Hartshorne.
Expressiveness, by R. Arnheim.
The expression theory of art, by O, K. Bouwsma.
The concept of expression in art, by V. Tomas, D. Morgan and M. Beardsley.
Musical expression, by M. Beardsley.
Expressive predicates of art, by G. Sircello.