Perhaps you should try some spelling variations:
thieu sach » chieu sach, thien hach, hieu cach
trinh quan » trinh han
hoc thieu » toc thieu, hoc hien
dung cong » dung trong
cong vang » cong lang, cong quang, cong ngang
vang phan » van phan, nang phan, quang phan
luat » luan, xuat

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 - hanh ((trinh luat) or (((trinh quan) OR (tinh quang)))) dung cong vang phan tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu sach - hanh ((trinh luat) OR (((trinh quan) OR (tinh quang)))) dung cong vang phan tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thieu sach - hanh ((trinh luat) or (((trinh quan) OR (tinh quang)))) dung cong vang phan tu".
• Adding a wildcard symbol may retrieve word variants: hoc thieu sach - hanh ((trinh luat) or (((trinh quan) OR (tinh quang)))) dung cong vang phan tu*.