Perhaps you should try some spelling variations:
nam thuoc » nam thuc, nam thu, nha thuoc
hang hoc » hang hoa, nang hoc, bang hoc
va hanh » van hanh, va thanh, va danh
te sach » toc sach
sach ty » sach y, sach tu, sach thu
hieu va » lieu va, hieu qua
hoc dai » hoc dan
ty hang » ly hang, ty xang, thi hang
tai va » thai va, mai va, dai va
thuc » thu

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ty hang hoc dai. hieu va ((am thuc) or (nam thuoc)) va hanh ((tai va) or (tri va)) trien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ty hang hoc dai. hieu va ((am thuc) OR (nam thuoc)) va hanh ((tai va) OR (tri va)) trien.
• Adding a wildcard symbol may retrieve word variants: te sach ty hang hoc dai. hieu va ((am thuc) or (nam thuoc)) va hanh ((tai va) or (tri va)) trien*.