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

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