Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
van hanh » van thanh, ban hanh, van anh
cham luu » cham cuu, chat lua, phap luu
hieu van » hieu va, thien van, lieu va
hang xa » hoang xa, hang ca, lang xa
luu van » cuu van, luan van, luu hanh
hieu ve » hieu va
sach ly » sach y, sach lo, sach ty
vi cua » vai cua, di cua
cua su » qua su

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc sach ly ((hang xa) or (hang va)) hoi. ((hieu ve) OR (hieu van)) cham luu van hanh vi cua su~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach ly ((hang xa) OR (hang va)) hoi. ((hieu ve) OR (hieu van)) cham luu van hanh vi cua su.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sach ly ((hang xa) or (hang va)) hoi. ((hieu ve) OR (hieu van)) cham luu van hanh vi cua su".
• Adding a wildcard symbol may retrieve word variants: hoc sach ly ((hang xa) or (hang va)) hoi. ((hieu ve) OR (hieu van)) cham luu van hanh vi cua su*.