Perhaps you should try some spelling variations:
thien hach » thien thanh, hien hanh
hanh trinh » canh tranh, hanh chinh
hoc thien » hoc hien, hoc thieu, hoc thiet
hang cong » dang cong, hang nong, bang cong
trinh va » trinh van, trinh vat, trinh ve
cong san » cong tac
toan cao » toan tap
toan ban » van ban
va hang » van hang, va nang, va lang

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc thien hach - hanh trinh va hang cong san ((toan cao) OR (toan ban))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thien hach - hanh trinh va hang cong san ((toan cao) OR (toan ban))".
• Adding a wildcard symbol may retrieve word variants: hoc thien hach - hanh trinh va hang cong san ((toan cao) OR (toan ban))*.