Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
thu nang » thi nang, thu hang, tho nang
thu bang » thu ban, thu hang, chu bang
va hanh » van hanh, va thanh, ban hanh
va danh » va dinh, va dan, dia danh
cao suc » cao su, cao duc
qua cao » qua cac, qua ca, qua cai
cua te » cua tu
o hoi » co hoi, o hoc, o hai

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuoc sach ((thu nang) OR (thu bang)) o hoi. hieu qua cao suc ((va danh) or (va hanh)) dai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach ((thu nang) OR (thu bang)) o hoi. hieu qua cao suc ((va danh) OR (va hanh)) dai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sach ((thu nang) OR (thu bang)) o hoi. hieu qua cao suc ((va danh) or (va hanh)) dai cua te".
• Adding a wildcard symbol may retrieve word variants: thuoc sach ((thu nang) OR (thu bang)) o hoi. hieu qua cao suc ((va danh) or (va hanh)) dai cua te*.