Perhaps you should try some spelling variations:
dua tren » dung tren
van hanh » van thanh, ban hanh, van anh
cham tuc » nham thuc, pham thuc, tham thuc
tu sach » thu sach, te sach, tu cach
tuc van » thuc van, truc van, tuc va
ve cham » va cham, ve chat, vu cham
hieu ve » hieu va, hieu van
su sach » so sach, vu sach
cuu tre » cua tre, cau tren, cau treo
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (su sach)) ky nang x hoi. hieu ve cham tuc van hanh vi ((dua tren) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ky nang x hoi. hieu ve cham tuc van hanh vi ((dua tren) OR (cuu tre)).
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (su sach)) ky nang x hoi. hieu ve cham tuc van hanh vi ((dua tren) or (cuu tre))*.