Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
dua tren » dung tren
hanh dai » hanh tai, hanh dao, vanh dai
hieu ve » hieu va, hieu van
va hanh » van hanh, va thanh, va danh
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
cuu tre » cua tre, cau tren, cau treo
tu sach » thu sach, su sach, te sach
ve cac » va cac, vien cac

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 ky nang xa hoi. hieu ve cac nuoc va hanh dai ((((dua tren) or (cuu tre))) or (va triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang xa hoi. hieu ve cac nuoc va hanh dai ((((dua tren) OR (cuu tre))) OR (va triet)).
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang xa hoi. hieu ve cac nuoc va hanh dai ((((dua tren) or (cuu tre))) or (va triet))*.