Perhaps you should try some spelling variations:
thien hach » thien thanh, hien hanh
hanh trang » thanh trung, canh tranh, hanh trinh
hien sach » dien sach, kien sach, chieu sach
dung cong » dung trong
vang tuan » van tuan, quang tuan, hoang tuan
vong tuan » vuong tuan, cong tuan, hoang tuan
trang va » tran van, hang va
va dung » van dung, va duong, vat dung

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) or (thien hach)) - hanh trang va dung cong ((vang tuan) OR (vong tuan)) bang~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hien sach) OR (thien hach)) - hanh trang va dung cong ((vang tuan) OR (vong tuan)) bang.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hien sach) or (thien hach)) - hanh trang va dung cong ((vang tuan) OR (vong tuan)) bang".
• Adding a wildcard symbol may retrieve word variants: hoc ((hien sach) or (thien hach)) - hanh trang va dung cong ((vang tuan) OR (vong tuan)) bang*.