Perhaps you should try some spelling variations:
thong cong » trong cong, tong cong, thong thong
hien xanh » hien hanh, hien nhanh, chieu xanh
trung lap » trung cap, truong lam, truong lop
trung dai » truong dai, truong dao, trung tam
cong hoan » cong hoa, dong hoa, cong san
hoan phan » hoa phan, toan phan, doan phan

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 xanh - hanh ((trung lap) or (trung dai)) thong cong hoan phan tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hien xanh - hanh ((trung lap) OR (trung dai)) thong cong hoan phan tu*.