Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
hieu vien » hieu hien, hieu viec, thieu nien
thi hang » thi hanh, thi hong, thi thanh
thi nang » thi cong, ki nang, thi hanh
vien cac » vien bach, vien dai, vien da
xa thanh » va thanh, ha thanh, ta thanh
cac tac » cac toc, cac bac, cac dac
tac xa » tuc xa, tac da
ve van » le van
o hoi » co hoi, o hoc, o hai
ke va » te va
thiet » thieu

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 ((thi hang) OR (thi nang)) o hoi. hieu vien cac tac xa thanh ((ve van) or (ke va)) thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach ((thi hang) OR (thi nang)) o hoi. hieu vien cac tac xa thanh ((ve van) OR (ke va)) thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sach ((thi hang) OR (thi nang)) o hoi. hieu vien cac tac xa thanh ((ve van) or (ke va)) thiet".
• Adding a wildcard symbol may retrieve word variants: thuoc sach ((thi hang) OR (thi nang)) o hoi. hieu vien cac tac xa thanh ((ve van) or (ke va)) thiet*.