Perhaps you should try some spelling variations:
sang mai » sang ma, sang tai, lang mai
mai khoi » mai khoa, tai khoa, cac khoi
nam duoc » nam thuoc, da duoc, dat duoc
hanh dao » lanh dao, thanh dat, thanh dam
hanh dai » hanh tai, vanh dai, thanh dat
cua tre » cua te, cuu tre, cua triet
ky sang » ky nang, ky dang, ky tang
hieu ve » hieu va, hieu van
te sac » te sach, te cac, te san
sac ky » cac ky, sai ky

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sac ky sang mai khoi. hieu ve ((nam duoc) or (cam xuc)) va ((hanh dai) OR (hanh dao)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sac ky sang mai khoi. hieu ve ((nam duoc) OR (cam xuc)) va ((hanh dai) OR (hanh dao)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sac ky sang mai khoi. hieu ve ((nam duoc) or (cam xuc)) va ((hanh dai) OR (hanh dao)) cua tre".
• Adding a wildcard symbol may retrieve word variants: te sac ky sang mai khoi. hieu ve ((nam duoc) or (cam xuc)) va ((hanh dai) OR (hanh dao)) cua tre*.