From the link to www.masterdissertations.com, I am guessing you are doing a Masters thesis, but even so, I would strongly advise looking first in Proquest's "Dissertations & Theses Fulltext" database. All major universities subscribe to this, and even some large colleges, but its title varies in the "Databases" or "Online resources" lists. Here at U of Maryland, we list it under Dissertations…, but many other places call it Proquest Dissertations. If you limit to "all fields - no full text" search, it gets 54 hits for the search: (nontraditional or "non traditional") and advertis*. If you search full text, which generally goes back only to about 1996, you would be well advised to use "proximity search", to look for words close together in those sometimes 100 + page dissertations. All Fields + Full text search for: (nontraditional or "non traditional") w/20 advertis* gets 116 hits, but I am not sure it really looks for either the word or the phrase within 20 words or less of advertis* (which includes advertise, advertisers, advertisement, advertising…, etc). Proximity search is safer doing single pairs of words/phrases at a time. I get 76 hits for "non traditional" w/20 advertise* and 42 for: nontraditional w/20 advertise*. Also, Proquest first gets 224 hits for fulltext search: (nontraditional OR "non traditional") w/20 advertise*, and asks: "Did you mean (nontraditional OR "non traditional") w/20 advertise*. When I clicked to re-search that hot-linked search, it gave 116 hits.
Academic Search (Ebsco) is a very good database to try, because it has a great deal of full text, and covers virtually all subjects. Bear in mind that non-traditional advertising could appear in widely varied journals - business, psychology, education, political, and even technical subjects such as computing (covered by big full text databases such as IEEE Xplore or ACM Digital Library). Academic Search Premier gets 156 results for: (nontraditional OR "non traditional") and advertise*, in its default search of author, title, journal name, subject, and abstract. Click "scholarly/peer reviewed" either before OR after the search to drop that to 35. Academic Search Premier gets 2 hits for: advertis* and banksy; if you "select a field TX-All Text, the proximity search: advertis* n40 banksy gets 11 hits - 3 scholarly. The search TX advertis* n40 graffiti gets 156 peer reviewed - but of course many could be about advertising campaigns to FIGHT graffiti.
Business Source Complete (also Ebsco) gets 312, but only 35 scholarly - maybe the same 35 as Academic Search? Many big universities will have Academic Search Complete - a bigger version than U of MD's "Premier" version, so you might get more hits than I did. IEEE Xplore gave very confusing results - a lot of hits for ("non traditional" OR nontraditional) AND advertis* - even in its default "Metadata Only" (not including full text), but it seemed to me it must be picking up the word nontraditional, etc. in advertisements in the IEEE journals. You may need to try quite a few different searches. If you get even a few GOOD articles, we can further explain how to look for articles that cite them.