Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac
hieu van » hieu va, thien van, lieu va
ban hanh » ban hang
luc ban » duc ban, cuc ban, luc bat
hoc anh » hoc nganh, hoc nhanh, ngoc anh
hanh di » hanh vi, hanh de, hang di
lang xa » lang ha, dang xay, lang van
cua tu » cua tuc, cua cu, cua te
van co » van cho, ban co, san co
co luc » coc luc, co luy
o lang » hoa lang, hoi lang
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) OR (hoc anh)) o lang xa hoi. hieu van co luc ban hanh di ((cua tu) or (cua su))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((hoc sach) OR (hoc anh)) o lang xa hoi. hieu van co luc ban hanh di ((cua tu) OR (cua su)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((hoc sach) OR (hoc anh)) o lang xa hoi. hieu van co luc ban hanh di ((cua tu) or (cua su))".
• Adding a wildcard symbol may retrieve word variants: ((hoc sach) OR (hoc anh)) o lang xa hoi. hieu van co luc ban hanh di ((cua tu) or (cua su))*.