Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, te sach, tu cach
danh vi » hanh vi, dinh vi, danh di
va danh » va dinh, va dan, va hanh
cam duc » cam xuc, cao duc, pham duc
cuu tre » cua tre, cau tren, cau treo
hieu ve » hieu va
su sach » so sach, vu sach
vi cuu » vi luu, vinh cuu
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) OR (hieu van)) cam duc va danh vi 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) OR (hieu van)) cam duc va danh vi cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (su sach)) ky nang x hoi. ((hieu ve) OR (hieu van)) cam duc va danh vi cuu tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (su sach)) ky nang x hoi. ((hieu ve) OR (hieu van)) cam duc va danh vi cuu tre*.