Perhaps you should try some spelling variations:
nam thuoc » nam thuc, nam thu, nha thuoc
dang xay » dang van, van xay
thuoc va » thuc va, thuoc ma, thuong va
cau tren » cu tren, dau tren, ca tren
sach ty » sach tu, sach thu, xach tay
xay hoi » xa hoi, tay hoi, cay phoi
sach ky » sac ky, sach kem, sach hay
hieu va » lieu va, hieu qua
va nam » van nam, ha nam, va nay
va dau » va dao
dau va » dau ve, lau va
va cau » van cau, va cac, va cao

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc ((sach ky) or (((sach ty) or (sach y)))) dang xay hoi. hieu va nam thuoc va dau va cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((sach ky) OR (((sach ty) OR (sach y)))) dang xay hoi. hieu va nam thuoc va dau va cau tren.
• Adding a wildcard symbol may retrieve word variants: doc ((sach ky) or (((sach ty) or (sach y)))) dang xay hoi. hieu va nam thuoc va dau va cau tren*.