Perhaps you should try some spelling variations:
dong thanh » truong thanh
thuc dong » thuoc dong, thuc dung, phuc dong
nam thuc » nam thuoc, am thuc, nam thu
sach ky » sac ky, sach y, sach ty
su sach » so sach, vu sach
hieu va » lieu va, hieu qua
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
vai ve » va ve, vai va, vi ve
dai ve » dap ve, dau ve, dai va
va nam » van nam, ha nam, va nay

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 ((nang xa) or (nang ma)) hoi. hieu va nam thuc dong thanh ((vai ve) OR (dai ve)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky ((nang xa) OR (nang ma)) hoi. hieu va nam thuc dong thanh ((vai ve) OR (dai ve)) triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky ((nang xa) or (nang ma)) hoi. hieu va nam thuc dong thanh ((vai ve) OR (dai ve)) triet*".