Perhaps you should try some spelling variations:
kien sach » dien sach, vien bach, kien mac
hanh tang » hanh trang, anh tang, hanh mang
hoc kien » hoc hien, hoc vien, hoa kien
cong san » cong tac
song van » hoang van, trong van, duong van
tang va » trang va, tang van, thang va
tai cao » thai cao, tai sao, tai cac
tao cao » bao cao, toan cao

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc kien sach - hanh tang va nhung ((cong san) or (song van)) ((tai cao) or (tao cao))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc kien sach - hanh tang va nhung ((cong san) OR (song van)) ((tai cao) OR (tao cao)).
• Adding a wildcard symbol may retrieve word variants: hoc kien sach - hanh tang va nhung ((cong san) or (song van)) ((tai cao) or (tao cao))*.