Perhaps you should try some spelling variations:
dat tren » dat trong, dua tren
thanh vi » hanh vi, thanh va, thanh ve
va thanh » gia thanh, ban thanh, va tinh
la tren » loai tren, dua tren, dau tren
cao duc » dao duc, cao suc, giao duc
su sach » so sach
hieu ve » hieu va, hieu van
vu sach » vu bach, vu khach
ve cao » va cao, ve bao, ve cac
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: ((su sach) or (vu sach)) ky nang x hoi. hieu ve cao duc va thanh vi ((la tren) OR (dat tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (vu sach)) ky nang x hoi. hieu ve cao duc va thanh vi ((la tren) OR (dat tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (vu sach)) ky nang x hoi. hieu ve cao duc va thanh vi ((la tren) OR (dat tren))".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (vu sach)) ky nang x hoi. hieu ve cao duc va thanh vi ((la tren) OR (dat tren))*.