Perhaps you should try some spelling variations:
nam thuoc » nam thuc, nam thu, nha thuoc
hieu van » hieu va, thien van, lieu va
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, su sach, tu cach
te sach » toc sach
va hanh » va thanh, va danh, ban hanh
cu tren » tu tren, dua tren
x hoi » xa hoi, o hoi, x ho
vi cu » vi su, vi xu, vi du

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) OR (te sach)) ky nang x hoi. hieu van nam thuoc ((va hanh) or (van hanh)) vi cu tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) ky nang x hoi. hieu van nam thuoc ((va hanh) OR (van hanh)) vi cu tren*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (te sach)) ky nang x hoi. hieu van nam thuoc ((va hanh) or (van hanh)) vi cu tren*".