Perhaps you should try some spelling variations:
dung tren » dung trong, dung trung
tham soc » tham nuoc, thai son, ham so
hieu van » thien van, lieu va, hieu ve
va dung » van dung, va duong, vat dung
hanh va » hang va, hanh vi
va hanh » van hanh, va thanh, va danh
lang xa » lang ha, dang xay, lang van
hieu va » lieu va, hieu qua
ky lang » ky nang, ky dang, ky tang
sac ky » cac ky, sai ky
te sac » te sach, te cac, te san

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sac ky lang xa hoi. ((hieu van) or (hieu va)) ((tham soc) OR (cham soc)) va hanh va dung tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sac ky lang xa hoi. ((hieu van) OR (hieu va)) ((tham soc) OR (cham soc)) va hanh va dung tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sac ky lang xa hoi. ((hieu van) or (hieu va)) ((tham soc) OR (cham soc)) va hanh va dung tren".
• Adding a wildcard symbol may retrieve word variants: te sac ky lang xa hoi. ((hieu van) or (hieu va)) ((tham soc) OR (cham soc)) va hanh va dung tren*.