Perhaps you should try some spelling variations:
dung dai » duong dai, dung tai, dung dat
su sach » so sach, vu sach
vu nang » vuc nang, va nang, vu dang
qua cam » qua cham, qua cac, qua ca
cam duc » cam xuc, cao duc, pham duc
va dung » van dung, va duong, vat dung
v nang » va nang, van nang, voi nang
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: su sach ((v nang) or (vu nang)) xa hoi. hieu qua cam duc va dung dai ((cua te) OR (cua tu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((v nang) OR (vu nang)) xa hoi. hieu qua cam duc va dung dai ((cua te) OR (cua tu)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((v nang) or (vu nang)) xa hoi. hieu qua cam duc va dung dai ((cua te) OR (cua tu))".
• Adding a wildcard symbol may retrieve word variants: su sach ((v nang) or (vu nang)) xa hoi. hieu qua cam duc va dung dai ((cua te) OR (cua tu))*.