Perhaps you should try some spelling variations:
trinh chuan » trinh han, trinh quan, trinh luan
theo chieu » theo tieu, ho chieu, theo chu
chieu sach » chinh sach, chiet tach, chieu sang
hanh trinh » canh tranh, hanh chinh
duong cong » luong cong, duong trong, trong cong
dung cong » dung trong
tac danh » sach danh, cac doanh, cac dan
danh cac » dinh cac, danh ca, hanh cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: theo chieu sach - hanh trinh chuan ((duong cong) or (dung cong)) tac danh cac~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo chieu sach - hanh trinh chuan ((duong cong) OR (dung cong)) tac danh cac.
• Adding a wildcard symbol may retrieve word variants: theo chieu sach - hanh trinh chuan ((duong cong) or (dung cong)) tac danh cac*.