Perhaps you should try some spelling variations:
thanh doi » thanh loi, thanh moi, thanh do
cua triet » cua viet, su triet, va triet
va thanh » gia thanh, ban thanh, va tinh
nang ma » tang ma, sang ma, nang cao
sach ky » sach y, sach ty, sach kem
cua tre » cua te, cuu tre, dua tren
hieu ve » hieu va, hieu van
sac ky » cac ky, sai ky
ma hoi » mai hoi, xa hoi, ma hoa
ve cac » va cac, vien cac
cac tu » cac thu, cach tu, cac du

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuoc ((sach ky) OR (sac ky)) nang ma hoi. hieu ve cac tu va thanh doi ((cua tre) or (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc ((sach ky) OR (sac ky)) nang ma hoi. hieu ve cac tu va thanh doi ((cua tre) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc ((sach ky) OR (sac ky)) nang ma hoi. hieu ve cac tu va thanh doi ((cua tre) or (cua triet))".
• Adding a wildcard symbol may retrieve word variants: thuoc ((sach ky) OR (sac ky)) nang ma hoi. hieu ve cac tu va thanh doi ((cua tre) or (cua triet))*.