Perhaps you should try some spelling variations:
tu sach » thu sach, te sach, tu cach
su sach » so sach, vu sach
hieu va » hieu qua
va hanh » van hanh, va thanh, va danh
luu tre » luu tru, cuu tre, luy tre
nam tu » nam thu, nam thuc
vi luu » vi lua
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 va) or (lieu va)) nam tu va hanh vi luu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ky nang x hoi. ((hieu va) OR (lieu va)) nam tu va hanh vi luu tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (su sach)) ky nang x hoi. ((hieu va) or (lieu va)) nam tu va hanh vi luu tre*.