Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
dang hai » dang khai, hang hai, dung hai
sach ky » sac ky, sach y, sach ty
mai hoi » mai khoi, dai hoi, lai hoi
hieu va » lieu va, hieu qua
va dang » van dang, va nang, va lang
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 ky nang ((ma hoi) or (mai hoi)). hieu va cac nuoc va dang hai ((cua te) OR (cua tu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach ky nang ((ma hoi) OR (mai hoi)). hieu va cac nuoc va dang hai ((cua te) OR (cua tu)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat sach ky nang ((ma hoi) or (mai hoi)). hieu va cac nuoc va dang hai ((cua te) OR (cua tu))".
• Adding a wildcard symbol may retrieve word variants: thuat sach ky nang ((ma hoi) or (mai hoi)). hieu va cac nuoc va dang hai ((cua te) OR (cua tu))*.