Perhaps you should try some spelling variations:
thieu sach » chieu sach, thien hach, hieu cach
thang viet » thong viet, trang viet, than viet
dung hoang » dang hoang, dung hong, khung hoang
hien hanh » dieu hanh
hang viet » hoang viet, nang viet, mang viet
hoang van » hang va
van thanh » ban thanh, van tuan
thanh tay » thanh tai, thanh toan, thanh thuy

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((thieu sach) or (hien hanh)) - nhanh ((thang viet) OR (hang viet)) dung hoang van thanh tay~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sach) OR (hien hanh)) - nhanh ((thang viet) OR (hang viet)) dung hoang van thanh tay.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu sach) or (hien hanh)) - nhanh ((thang viet) OR (hang viet)) dung hoang van thanh tay".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sach) or (hien hanh)) - nhanh ((thang viet) OR (hang viet)) dung hoang van thanh tay*.