1. Abstract and Concrete Categories;Adámek,1990
2. Approach spaces: A common supercategory of top and met;Lowen;Mathematische Nachrichten,1989
3. Approach spaces: The Missing Link in the Topology–Uniformity–Metric Triad;Lowe,1997
4. Approximations in functional analysis;Lowen;Results in Mathematics,2000
5. Approach vector spaces;Lowen;Houston Journal of Mathematics,2004