Perhaps you should try some spelling variations:
thien van » thi van
hieu van » hieu va, lieu va, hieu ve
chua tre » chua tri, cua tre, chua trieu
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
cau hoc » cau hoi, cau hoa, cao hoc
va hanh » van hanh, va thanh, va danh
hanh va » hang va, hanh vi
va chua » vua chua, ca chua, va chu

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 ho) or (xa hoi)). ((hieu van) or (thien van)) cau hoc va hanh va chua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang ((x ho) OR (xa hoi)). ((hieu van) OR (thien van)) cau hoc va hanh va chua tre.
• Adding a wildcard symbol may retrieve word variants: su sach ky nang ((x ho) or (xa hoi)). ((hieu van) or (thien van)) cau hoc va hanh va chua tre*.