Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
dua tren » dung tren
cau treo » cau theo, cau tren, cau triet
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
van cau » van dau, van hau, van chat
truc va » thuc va, thuc vat, trung va
va dan » ca dan, va dao, va dau
dan vi » doan vi, don vi, dan va

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 ky nang xa hoi. hieu van cau truc va dan vi ((dua tren) or (cau treo))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang xa hoi. hieu van cau truc va dan vi ((dua tren) OR (cau treo)).
• Adding a wildcard symbol may retrieve word variants: su sach ky nang xa hoi. hieu van cau truc va dan vi ((dua tren) or (cau treo))*.