Perhaps you should try some spelling variations:
thanh trung » thanh tung
khong thong » thong thong, khong trong, thong thuong
chieu sang » chieu sach, chieu xanh, hieu lang
trung hua » trung ha, trung hoa, trung cua
hua khong » hoa khong, cua khong, hoac khong
thong dan » thong van, tuong dan, thong den
phan cau » phan dau, phan cac, phan lap
hieu va » lieu va, hieu qua

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

• Performing a fuzzy search may retrieve terms with similar spellings: doi ((hieu va) or (chieu sang)) - thanh trung hua khong thong dan ((phan cau) OR (phan tu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi ((hieu va) OR (chieu sang)) - thanh trung hua khong thong dan ((phan cau) OR (phan tu)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi ((hieu va) or (chieu sang)) - thanh trung hua khong thong dan ((phan cau) OR (phan tu))".
• Adding a wildcard symbol may retrieve word variants: doi ((hieu va) or (chieu sang)) - thanh trung hua khong thong dan ((phan cau) OR (phan tu))*.