Interpolation, Definability and Fixed Points in Interpretability Logics. - Carlos Areces; Eva Hoogland; Dick de Jongh (Advances in Modal Logic, 1998)

Beth Definability for the Guarded Fragment. - Eva Hoogland; Maarten Marx; Martin Otto 001 (LPAR, 1999)

Algebraic Characterizations of Various Beth Definability Properties. - Eva Hoogland (Stud Logica, 2000)

Interpolation and Definability in Guarded Fragments. - Eva Hoogland; Maarten Marx (Stud Logica, 2002)

The Beth Property in Algebraic Logic. - Willem J. Blok; Eva Hoogland (Stud Logica, 2006)