Perhaps you should try some spelling variations:
nam thuoc » nam thuc, nam thu, nha thuoc
thuoc vat » thuc vat, thuoc va, thuoc bat
sach ty » sach y, sach tu, sach thu
hanh de » hanh ve, hanh kem
hanh di » hanh vi, hang di, danh di
hieu ve » hieu va, hieu van
nang xa » nang x, lang xa, nang ma
cua tre » cua te, cuu tre, cua triet
ve nam » he nam, va nam, le nam
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: su ((sach ty) or (sac ky)) nang xa hoi. hieu ve nam thuoc vat ((hanh di) OR (hanh de)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ty) OR (sac ky)) nang xa hoi. hieu ve nam thuoc vat ((hanh di) OR (hanh de)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ty) or (sac ky)) nang xa hoi. hieu ve nam thuoc vat ((hanh di) OR (hanh de)) cua tre".
• Adding a wildcard symbol may retrieve word variants: su ((sach ty) or (sac ky)) nang xa hoi. hieu ve nam thuoc vat ((hanh di) OR (hanh de)) cua tre*.