Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
nam thuoc » nam thuc, nam thu, nha thuoc
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu va » hieu qua
va hanh » van hanh, va thanh, va danh
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 ky nang x hoi. ((hieu va) OR (lieu va)) nam thuoc ((va hanh) or (van thanh)) vi cu tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang x hoi. ((hieu va) OR (lieu va)) nam thuoc ((va hanh) OR (van thanh)) vi cu tren*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang x hoi. ((hieu va) OR (lieu va)) nam thuoc ((va hanh) or (van thanh)) vi cu tren*".