Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
hieu van » hieu va, thien van, hieu ve
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
dong tai » dung tai, luong tai, cong tac
sach ky » sac ky, sach y, sach ty
mai hoi » mai khoi, dai hoi, lai hoi
nuoc ha » nuoc va, ngoc ha, nuoc ta
ha dong » hoat dong, van dong
tai cua » thai cua, tai cuc, tri cua
ma hoi » xa hoi, ma hoa, me hoi
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: thuat sach ky nang ((ma hoi) or (mai hoi)). ((hieu van) OR (lieu va)) cac nuoc ha dong tai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach ky nang ((ma hoi) OR (mai hoi)). ((hieu van) OR (lieu va)) cac nuoc ha dong tai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat sach ky nang ((ma hoi) or (mai hoi)). ((hieu van) OR (lieu va)) cac nuoc ha dong tai cua te".
• Adding a wildcard symbol may retrieve word variants: thuat sach ky nang ((ma hoi) or (mai hoi)). ((hieu van) OR (lieu va)) cac nuoc ha dong tai cua te*.