Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
danh vi » hanh vi, dinh vi, danh di
va danh » va dinh, va dan, va hanh
cac dac » cac dan, cac dai, cac bac
hieu va » lieu va, hieu qua
tu sach » thu sach, te sach, tu cach
su sach » so sach, vu sach
cac duc » cac du, cao duc, cac nuoc
vi cau » va cau, ve cau, di cau
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 ((cac duc) or (cac dac)) va danh vi cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ky nang x hoi. hieu va ((cac duc) OR (cac dac)) va danh vi cau tren.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (su sach)) ky nang x hoi. hieu va ((cac duc) or (cac dac)) va danh vi cau tren*.