Perhaps you should try some spelling variations:
nam thuoc » nam thuc, nam thu, nha thuoc
vat thanh » dat thanh, gat thanh, tat thanh
vat hanh » van hanh, va hanh, nhat hanh
sach ky » sach y, sach ty, sach kem
doi cua » dai cua, hoi cua
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 ky) or (sac ky)) nang xa hoi. hieu ve nam thuoc ((vat hanh) OR (vat thanh)) doi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sac ky)) nang xa hoi. hieu ve nam thuoc ((vat hanh) OR (vat thanh)) doi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ky) or (sac ky)) nang xa hoi. hieu ve nam thuoc ((vat hanh) OR (vat thanh)) doi cua tre".
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) or (sac ky)) nang xa hoi. hieu ve nam thuoc ((vat hanh) OR (vat thanh)) doi cua tre*.