I am surprised that a less specific keyword search came up with some better studies. Previously I was using terms like "native-speaking English teachers," "English as a foreign language," "intercultural communication," "intercultural competence," and various combinations of these terms. These results have given me plenty of literature for a theoretical framework for intercultural communication competence training for EFL instructors, but they didn't provide enough examples of how to investigate EFL instructors dealing with the culture(s) of the classroom abroad. So I'm a bit surprised that "teaching abroad" yielded better results without mention of culture or teaching English.
My database of choice for the past year has been Wilson Web. I have used others, but Wilson Web has turned up the most and best literature. It also seems to "understand" my keyword searches better.
The treasure I found is a short article on a lengthy qualitative study of native-speaking English teachers teaching writing in Chinese universities. Although I was disappointed that the list of references was shorter than I expected, it helped me locate a couple more treasures. Reading through these studies confirms that there haven't been enough studies about this topic, but there is a big need for it, which leads me to another treasure. I have more support to build a stronger case for carrying out my research.
I have yet to find a lengthy study or a dissertation that closely matches my research interest, but I'm finding the right researchers who may be able to point me in the right direction. I am very excited about what I may find, but I understand that I may be setting myself up for disappointment.