Perhaps you should try some spelling variations:
vat dung » van dung, va dung, viet dung
sach ty » sach tu, sach thu, xach tay
qua cam » qua cham, qua cac, qua ca
cam tuc » cam xuc, cam tu, nam thuc
tuc vat » thuc vat, tuc va, tuc hat
doi cua » hoi cua
nang o » nang co, nang ho, nang ro
o hoi » co hoi, o hoc, o hai

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