Perhaps you should try some spelling variations:
chiet tach » chieu sach
hoc chiet » hoc thiet, hoc nhiet, hoc hien
trinh vin » trinh van, trinh tin, trinh ven
cong vang » cong lang, cong quang, cong ngang
trinh vi » trinh va, trinh ve, trinh viet
cong san » cong tac
phan tap » phan lap, han tap, pha tap

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc chiet tach - hanh ((trinh vi) or (trinh vin)) hang ((cong san) or (cong vang)) phan tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc chiet tach - hanh ((trinh vi) OR (trinh vin)) hang ((cong san) OR (cong vang)) phan tap.
• Adding a wildcard symbol may retrieve word variants: hoc chiet tach - hanh ((trinh vi) or (trinh vin)) hang ((cong san) or (cong vang)) phan tap*.