Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
cac nuoc » cap nuoc, dat nuoc, cua nuoc
dang hai » dang khai, hang hai, dung hai
mai hoi » mai khoi, dai hoi, lai hoi
hieu va » lieu va, hieu qua
va dang » van dang, va nang, va lang
hai cua » thai cua, dai cua, hoi cua
y nang » ky nang, ly nang, v nang
ma hoi » xa hoi, ma hoa, me hoi
cua tu » cua tuc, cua su, cua cu

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 y nang ((ma hoi) or (mai hoi)). hieu va ((cac nuoc) or (hoc nuoc)) va dang hai cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach y nang ((ma hoi) OR (mai hoi)). hieu va ((cac nuoc) OR (hoc nuoc)) va dang hai cua tu.
• Adding a wildcard symbol may retrieve word variants: thuat sach y nang ((ma hoi) or (mai hoi)). hieu va ((cac nuoc) or (hoc nuoc)) va dang hai cua tu*.