Following up on those commercial databases, Academic Search Premier gets only 4 articles for the search: "debtor* union*", even when you "select a field" TX-All Text. That * truncation includes variant phrases such as: debtor unions, debtors union, debtors unionized, etc. But a fairly wide "proximity search" might help locate a few relevant articles that are well hidden among articles that may be very broadly indexed under such things as protest movements, activism, etc. For example, Academic Search Premier gets 89 articles for the TX All Text search: Debtor* n10 union*. The vast majority of these mention Union Bank...., European Union...., etc. But record no. 7 is:
Occupy 2.0: Strike Debt. Full Text Available. By: TAYLOR, ASTRA. Nation. 9/24/2012, Vol. 295 Issue 13, p17-20. 3p.Subjects: OCCUPY protest movement; PROTEST movements; DEBT; STUDENT loans; COLLEGE costs; CONSUMER credit; FORECLOSURE; PUBLIC debts; DEBT cancellation; UNITED States; Consumer Lending; Public Finance Activities. Database: Academic Search Premier
Limiting to "scholarly/peer reviewed" gets only 53 articles, and there seem to be very few talking about debtor's unions. But no. 15 is:
The Struggle for Public Education in California: Coming Due: Accounting for Debt, Counting on Crisis. Images Authors: McClanahan, Annie Source: South Atlantic Quarterly; Spring2011, Vol. 110 Issue 2, p539-545, 7p, 1 Graph
This article does discuss UC Berkeley student protests against higher tuition and student debt. Another possible TX All text search is: Debtor* n5 strike* (17 articles, 12 of them peer reviewed), or Debtor* n5 protest* (15, 9 peer rev)
JSTOR is available at most academic and at a few large public libraries. But it comes in many different sized "packages", so my searches only show what it finds at U of Maryland. The proximity search: "debtors unions"~5 gets 10 articles, where those words are within 5 words of each other somewhere in each article. "Debtors strikes"~5 gets 6. But JSTOR articles can be 15-20 or more pages long, and it usually does NOT link to "pages with your search terms". It can be very time consuming to look for relevant information, but the trade-off is that JSTOR does have very scholarly articles.
Proquest Dissertations & Theses Fulltext might give some leads. By default it searches full text, and the proximity search: Debtor* w/5 strike* gets 3 results. A good alternative in Proquest is their "all fields, no full text" search, in advanced search, where: Debtor* and (strike* or striking or protest*) gets 10 results, and you can look at the citation and abstract without having to plow through maybe a 100+ page dissertation.