Perhaps you should try some spelling variations:
xanh hanh » danh thanh, van hanh, dang hanh
hieu van » hieu va, thien van, lieu va
ban hanh » ban hang
dua tren » dung tren
tu lang » cu lang, tu lanh, xu lang
lang ky » dang ky, tang ky, bang ky
cao hoi » cau hoi, co hoi, cao hoc
van cao » van dao, van bao, van hao
cao suc » cao su, cao duc
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu lang ky nang cao hoi. hieu van cao suc ((xanh hanh) OR (ban hanh)) tai ((dua tren) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu lang ky nang cao hoi. hieu van cao suc ((xanh hanh) OR (ban hanh)) tai ((dua tren) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu lang ky nang cao hoi. hieu van cao suc ((xanh hanh) OR (ban hanh)) tai ((dua tren) or (cua te))".
• Adding a wildcard symbol may retrieve word variants: tu lang ky nang cao hoi. hieu van cao suc ((xanh hanh) OR (ban hanh)) tai ((dua tren) or (cua te))*.