Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
dang thai » dang thi, dang hai, dang khai
hieu van » hieu va, thien van, lieu va
thai cua » than cua, tai cuc, tri cua
cap nuoc » dat nuoc
cau nuoc » cac nuoc, dau nuoc, chua nuoc
va dang » van dang, va nang, va lang
sach ky » sac ky, sach y, sach ty
mai hoi » mai khoi, dai hoi, lai hoi
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 ((cau nuoc) OR (cap nuoc)) va dang thai 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 ((cau nuoc) OR (cap nuoc)) va dang thai 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 ((cau nuoc) OR (cap nuoc)) va dang thai cua te".
• Adding a wildcard symbol may retrieve word variants: thuat sach ky nang ((ma hoi) or (mai hoi)). hieu van ((cau nuoc) OR (cap nuoc)) va dang thai cua te*.