Perhaps you should try some spelling variations:
nang hang » nang sang, hang hang, cang thang
nang han » nang phan, nang hanh, nang ban
va thanh » gia thanh, ban thanh, va tinh
cua tre » cua te, cuu tre, cua triet
va hanh » van hanh, va danh, ban hanh
tai cua » thai cua, tai cuc, tri cua
hieu va » lieu va, hieu qua
cau luc » cau truc, cau phuc
su sai » su tai, su hai, su dai
sai ky » sac ky
va cau » van cau, va cac, va dau

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: su sai ky ((nang han) OR (nang hang)) hoi. hieu va cau luc ((va hanh) or (va thanh)) tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sai ky ((nang han) OR (nang hang)) hoi. hieu va cau luc ((va hanh) OR (va thanh)) tai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sai ky ((nang han) OR (nang hang)) hoi. hieu va cau luc ((va hanh) or (va thanh)) tai cua tre".
• Adding a wildcard symbol may retrieve word variants: su sai ky ((nang han) OR (nang hang)) hoi. hieu va cau luc ((va hanh) or (va thanh)) tai cua tre*.