Revolutions in Modern English Drama (Bell & Hyman, 1973)Beckett the Shape Changer (Routledge, 1975)The Irish Drama of Europe from Yeats to Beckett (Athlone Press, 1978)Oscar Wilde (Macmillan, 1983)Maeterlinck's Plays in Performance (Chadwyck-Healey, 1985)Waiting for Godot and Happy Days: Text and Performance (Houndmill/Macmillan, 1990)Sheridan and Goldsmith (Houndmill, 1992)