I popped the citation into Duck Duck Go and found that I could access the article through Sage.
It was my understanding that most academic institutions have access to Sage journals online through their libraries?
My library does not have access to Sage.
I checked academia.edu ( https://www.academia.edu/1491218/Ethnicity_Comes_of_Age_An_Overview_of_Twentieth_Century_Terms_for_Ioudaios ) and the article is not uploaded there - you can ask the author for it...
It seems from https://journals.sagepub.com/doi/abs/10.1177/1476993X11428924 you might be able to access it for free through a trial membership of DeepDyve (whatever that may be). Other than that, it's available to buy - not a cheap route, I see.