Perhaps you should try some spelling variations:
thong dong » thong duong, thuong dong, thong cong
hien tinh » khien tinh, thien tinh, bien tinh
trung dap » trung cap, trung dam, trung lap
trung dai » truong dai, truong dao, trung tam
dong dan » dong danh, duong dan, dong san
dan phan » doan phan, dan chan, van phan
phan cau » phan dau, phan cac, phan tu

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: hoc hien tinh - hanh ((trung dap) or (trung dai)) thong dong dan phan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hien tinh - hanh ((trung dap) OR (trung dai)) thong dong dan phan cau*.