The pullback closure operator and generalisations of perfectness. - David B. Holgate (Appl. Categorical Struct., 1996)

Direct Reflections. - Guillaume C. L. Brümmer; Eraldo Giuli; David B. Holgate (Appl. Categorical Struct., 2000)

A Link Between Two Connectedness Notions. - Gabriele Castellini; David B. Holgate (Appl. Categorical Struct., 2003)

Connected and Disconnected Maps. - Gareth Boxall; David B. Holgate (Appl. Categorical Struct., 2011)

Topogenous and Nearness Structures on Categories. - David B. Holgate; Minani Iragi; Ando Razafindrakoto (Appl. Categorical Struct., 2016)

A Lax Approach to Neighbourhood Operators. - Ando Razafindrakoto; David B. Holgate (Appl. Categorical Struct., 2017)

Codenseness and Openness with Respect to an Interior Operator. - Fikreyohans Solomon Assfaw; David B. Holgate (Appl. Categorical Struct., 2021)