Perhaps you should try some spelling variations:
hien sach » dien sach, kien sach, thien hach
trinh ven » trinh van, trinh den, tinh ven
dung cong » dung trong
cong lang » cong vang, cong luong, cong quang
lang toan » dang toan, lang thang, lang thanh
trinh ve » trinh he, trinh va, trinh vi
toan ban » van ban

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc hien sach - hanh ((trinh ve) or (trinh ven)) dung cong lang toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hien sach - hanh ((trinh ve) OR (trinh ven)) dung cong lang toan ban.
• Adding a wildcard symbol may retrieve word variants: hoc hien sach - hanh ((trinh ve) or (trinh ven)) dung cong lang toan ban*.