Perhaps you should try some spelling variations:
thuoc sac » thuoc sach, thuoc dac, thuoc sai
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va, hieu van
ve pham » vi pham, v pham, ve phan
duc vat » duy vat, duc van, thuc vat
doi cua » dai cua
hoi cua » hoi chuc
sac ky » cac ky, sai ky

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

• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sac ky nang xa hoi. hieu ve pham ((duc vat) OR (duc va)) hanh ((doi cua) OR (hoi cua)) te~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sac ky nang xa hoi. hieu ve pham ((duc vat) OR (duc va)) hanh ((doi cua) or (hoi cua)) te~".
• Adding a wildcard symbol may retrieve word variants: thuoc sac ky nang xa hoi. hieu ve pham ((duc vat) OR (duc va)) hanh ((doi cua) or (hoi cua)) te*.