If you're blessed with knowledge of a foreign language—or, for the more adventorous, even if you're not—one of the best sources to plagiarize is the wealth of non-English scholarship available at your school library: French, German, Spanish, Russian, you name it. If you can read it, it can be plagiarized. And, if you can't read it, you can still put it to good use (see: foreign mis-attribution).
However, there are several factors to consider when choosing non-English sources for plagiarism.
1) You have to decide how obscure you want to go. Normally, the mid-to-obscure route is the safest because it gives you the greatest chance of hitting the sweet spot: that grey area between what your teacher has heard about and what seems so obscure that it's fishy. Seem original without seeming crazy. Although, obviously, it depends on your own particular context.
2) You have to know something about your teacher. If he or she speaks English and German, for instance, don't pick a German source! Also, remember that just because you've found something in a foreign language, doesn't mean it's not available in English, too—either in translation or because what you've found is a translation.
3) Check any footnotes in the source you choose to plagiarize. It could very well be that what you think is a great idea in an unknown Swahili source is actually from a popular English-language treatise that your teacher has on his or her shelf. Find the roots of ideas, and plagiarize only if they're shallow and firmly implanted in foreign soil.
However, there are several factors to consider when choosing non-English sources for plagiarism.
1) You have to decide how obscure you want to go. Normally, the mid-to-obscure route is the safest because it gives you the greatest chance of hitting the sweet spot: that grey area between what your teacher has heard about and what seems so obscure that it's fishy. Seem original without seeming crazy. Although, obviously, it depends on your own particular context.
2) You have to know something about your teacher. If he or she speaks English and German, for instance, don't pick a German source! Also, remember that just because you've found something in a foreign language, doesn't mean it's not available in English, too—either in translation or because what you've found is a translation.
3) Check any footnotes in the source you choose to plagiarize. It could very well be that what you think is a great idea in an unknown Swahili source is actually from a popular English-language treatise that your teacher has on his or her shelf. Find the roots of ideas, and plagiarize only if they're shallow and firmly implanted in foreign soil.