Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
sach ky » sac ky, sach y, sach ty
nang xa » nang x, nang ma, mang xa
lang xa » lang ha, dang xay, lang van
van bac » van ban, van bao, dan bac
van hac » van hoc, van ha, van hai
va dung » van dung, va duong, vat dung
cuc te » cua te, cuc thue, cuc tieu

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 xa) or (lang xa)) hoi. hieu ((van bac) OR (van hac)) nuoc va dung tai cuc te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach ky ((nang xa) OR (lang xa)) hoi. hieu ((van bac) OR (van hac)) nuoc va dung tai cuc te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat sach ky ((nang xa) or (lang xa)) hoi. hieu ((van bac) OR (van hac)) nuoc va dung tai cuc te".
• Adding a wildcard symbol may retrieve word variants: thuat sach ky ((nang xa) or (lang xa)) hoi. hieu ((van bac) OR (van hac)) nuoc va dung tai cuc te*.