Your recent editing history at Ian Nairn shows that you are currently engaged in an edit war. Being involved in an edit war can result in your being blocked from editing—especially if you violate the three-revert rule, which states that an editor must not perform more than three reverts on a single page within a 24-hour period. Undoing another editor's work—whether in whole or in part, whether involving the same or different material each time—counts as a revert. Also keep in mind that while violating the three-revert rule often leads to a block, you can still be blocked for edit warring—even if you don't violate the three-revert rule—should your behavior indicate that you intend to continue reverting repeatedly.
To avoid being blocked, instead of reverting please consider using the article's talk page to work toward making a version that represents consensus among editors. See BRD for how this is done. You can post a request for help at a relevant noticeboard or seek dispute resolution. In some cases, you may wish to request temporary page protection.
You have been asked to provide a reference for the edit you made. Gordon Cullen - the illustrator and art editor at Architectural Review - should not be called a "co-author" unless a reliable source also describes him as such. While not disputing that Cullen illustrated some of Nairn's work, it is a stretch of credibility to say that he authored the works with Nairn. Do not persist in undoing edits - find a reference. Alternatively, discuss the issue on the article's talk page. Blackberry Sorbet (talk • contribs) 12:09, 23 February 2014 (UTC)