Perhaps you should try some spelling variations:
nam thuc » nam thuoc, am thuc, nam thu
vat dung » van dung, va dung, viet dung
dung doi » huong doi, dung tai, dung co
sach ty » sach tu, sach thu, xach tay
nang xa » nang x, lang xa, nang ma
cam tuc » cam xuc, cam tu, dam thuc
doi cua » dai cua, hoi cua
cua tre » cua te, cuu tre, cua triet

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: su ((sach ty) or (sach y)) nang xa hoi. hieu qua ((cam tuc) OR (nam thuc)) vat dung doi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ty) OR (sach y)) nang xa hoi. hieu qua ((cam tuc) OR (nam thuc)) vat dung doi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ty) or (sach y)) nang xa hoi. hieu qua ((cam tuc) OR (nam thuc)) vat dung doi cua tre".
• Adding a wildcard symbol may retrieve word variants: su ((sach ty) or (sach y)) nang xa hoi. hieu qua ((cam tuc) OR (nam thuc)) vat dung doi cua tre*.