Perhaps you should try some spelling variations:
hanh trinh » canh tranh, hanh chinh
trinh tuan » trinh quan, trinh toan, trinh luan
doi chieu » doc hieu, ho chieu, mot chieu
tuan hang » tuan hoang, tuan bang, tuan dang
hang cong » dang cong, hang nong, bang cong
cong tan » cong tac, cong san, cong thanh
tran van » luan van
doi chi » doi khi

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((doi chieu) OR (doi chi)) sach - hanh trinh tuan hang cong tan tran van~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((doi chieu) OR (doi chi)) sach - hanh trinh tuan hang cong tan tran van".
• Adding a wildcard symbol may retrieve word variants: ((doi chieu) OR (doi chi)) sach - hanh trinh tuan hang cong tan tran van*.