Perhaps you should try some spelling variations:
hanh dai » hanh tai, hanh dao, vanh dai
dua tren » dung tren
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
cam duc » cam xuc, cao duc, pham duc
va hanh » van hanh, va thanh, va danh
ve cam » ve cham, ve cac, va cam
cua tu » cua tuc, cua su, cua cu
x hoi » xa hoi, x ho, 5 hoi
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 ky nang ((x hoi) OR (o hoi)). hieu ve cam duc va hanh dai ((dua tren) or (cua tu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang ((x hoi) OR (o hoi)). hieu ve cam duc va hanh dai ((dua tren) OR (cua tu))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang ((x hoi) OR (o hoi)). hieu ve cam duc va hanh dai ((dua tren) or (cua tu))*".