Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hieu va » lieu va, hieu qua
ty hang » ly hang, thi hang, thu hang
danh va » doanh va, hanh va, anh va
va danh » va dinh, va dan, va hanh
hieu ve » hieu van
duoc va » nuoc va, duc va, duoc ma
va cua » va chua, via cua, ca cua
cua cu » cua chu, cua cau, cua su
ca hoi » cau hoi, cua hoi, xa hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ((ty hang) OR (ty xang)) ca hoi. ((hieu ve) or (hieu va)) tao duoc va danh va cua cu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ((ty hang) OR (ty xang)) ca hoi. ((hieu ve) OR (hieu va)) tao duoc va danh va cua cu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ((ty hang) OR (ty xang)) ca hoi. ((hieu ve) or (hieu va)) tao duoc va danh va cua cu".
• Adding a wildcard symbol may retrieve word variants: thu sach ((ty hang) OR (ty xang)) ca hoi. ((hieu ve) or (hieu va)) tao duoc va danh va cua cu*.