Perhaps you should try some spelling variations:
hang van » hoang van, dang van, tang van
hoc sach » hoc sinh, hoc anh
thanh di » thanh doi, thanh de, thanh do
cau tren » cu tren, dau tren, ca tren
hoc cac » hoc cao
hieu ve » hieu va, hieu van
luc gia » luoc gia, duc gia, quoc gia
ve coc » ve cuoc, ve cac, ve co
di cau » da cau, diem cau

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 cac)) ty ((hang van) or (hang va)) hoi. hieu ve coc luc gia thanh di cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((hoc sach) OR (hoc cac)) ty ((hang van) OR (hang va)) hoi. hieu ve coc luc gia thanh di cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((hoc sach) OR (hoc cac)) ty ((hang van) or (hang va)) hoi. hieu ve coc luc gia thanh di cau tren".
• Adding a wildcard symbol may retrieve word variants: ((hoc sach) OR (hoc cac)) ty ((hang van) or (hang va)) hoi. hieu ve coc luc gia thanh di cau tren*.