You can search ProQuest Nursing & Allied Health for publications specific to national/ethnic groups.
One such publication is called CultureGram. CultureGram articles give a general information about a nation's land and climate, history, population, language, religion, dress, customs, courtesies, gestures, food, family and social structures and more that can help you understand your patient and how to care for them.
Example: "vietnam and culturegrams"
To learn how to search ProQuest Nursing & Allied Health, go to this guide.