A projective homotopy theory of crossedG-modules. - Graham Ellis; Keith A. Hardie (Appl. Categorical Struct., 1995)

A Homotopy 2-Groupoid of a Hausdorff Space. - Keith A. Hardie; Klaus Heiner Kamps; R. W. Kieboom (Appl. Categorical Struct., 2000)

A Homotopy Bigroupoid of a Topological Space. - Keith A. Hardie; Klaus Heiner Kamps; R. W. Kieboom (Appl. Categorical Struct., 2001)

A non-Hausdorff quaternion multiplication. - Keith A. Hardie; S. Salbany; J. J. C. Vermeulen; Peter J. Witbooi (Theor. Comput. Sci., 2003)

Triple Brackets and Lax Morphism Categories. - Keith A. Hardie; Klaus Heiner Kamps; Howard J. Marcum; Nobuyuki Oda (Appl. Categorical Struct., 2004)

A 2-groupoid Characterisation of the Cubical Homotopy Pushout. - Keith A. Hardie; Klaus Heiner Kamps; Peter J. Witbooi (Appl. Categorical Struct., 2004)

Finite relational structure models of topological spaces and maps. - Keith A. Hardie; Peter J. Witbooi (Theor. Comput. Sci., 2008)

A Coherent Homotopy Category of 2-track Commutative Cubes. - Keith A. Hardie; Klaus Heiner Kamps; Peter J. Witbooi (Appl. Categorical Struct., 2011)

The Fibre of a Pinch Map in a Model Category. - Keith A. Hardie; Peter Joseph Witbooi (Appl. Categorical Struct., 2013)