Query about citations

One defines the category of Diagrams on category A, Diag(A), as in Makkai & Pare's "Accessible Categories". One similarly defines the category of cones on diagrams on A and the category of cocones on diagrams on A. Limits and colimits exist when certain adjunctions hold between these derived categories. I am sure I have seen one or more papers or monographs giving the details for the above. I simply cannot recall where this (these) workout(s) appeared. I would like to (re)read the paper(s), so I would greatly appreciate receiving reminders about where to look for these results. Thank you in advance. With the warmest of season's greetings, David