Fibrations and partial products in a 2-category. - Peter T. Johnstone (Appl. Categorical Struct., 1993)

Variations on the Bagdomain Theme. - Peter T. Johnstone (Theor. Comput. Sci., 1994)

Connected Limits, Familial Representability and Artin Glueing. - Aurelio Carboni; Peter T. Johnstone (Math. Struct. Comput. Sci., 1995)

Finitary Sketches. - Jirí Adámek; Peter T. Johnstone; Johann A. Makowsky; Jirí Rosický (J. Symb. Log., 1997)

An Axiomatics for Categories of Transition Systems as Coalgebras. - Peter T. Johnstone; John Power; Toru Tsujishita; Hiroshi Watanabe 002; James Worrell 001 (LICS, 1998)

Classifying Toposes for First-Order Theories. - Carsten Butz; Peter T. Johnstone (Ann. Pure Appl. Log., 1998)

An "Unsitely" Result on Atomic Morphisms. - Peter T. Johnstone (Appl. Categorical Struct., 2000)

On the structure of categories of coalgebras. - Peter T. Johnstone; John Power; Toru Tsujishita; Hiroshi Watanabe 002; James Worrell 001 (Theor. Comput. Sci., 2001)

Corrigenda for 'Connected limits, familial representability and Artin glueing'. - Aurelio Carboni; Peter T. Johnstone (Math. Struct. Comput. Sci., 2004)

Complemented sublocales and open maps. - Peter T. Johnstone (Ann. Pure Appl. Log., 2006)

Quasitoposes, Quasiadhesive Categories and Artin Glueing. - Peter T. Johnstone; Stephen Lack; Pawel Sobocinski 001 (CALCO, 2007)

Foreword - Special Issue Dedicated to the Memory of Professor Gregory Maxwell Kelly. - George Janelidze; Martin Hyland; Michael Johnson; Peter T. Johnstone; Stephen Lack; Ross Street; Walter Tholen; Richard J. Wood (Appl. Categorical Struct., 2011)

What do Freyd's Toposes Classify? - Peter T. Johnstone (Logica Universalis, 2013)