Perhaps you should try some spelling variations:
thiet tach » chiet tach, thien hach, thuat tach
hanh trinh » canh tranh, hanh chinh
hoc thiet » hoc thieu, hoc thuyet, hoc hien
trinh cua » tinh cua, trinh luat, trinh quan
cua chung » cua nhung, luan chung, luat chung
vuong dan » huong dan, tuong dan, vuong dao
xuong dan » huong dan, xuong san, tuong dan
toan cau » toan cao, toan ban, toan tai
toan tap » toan ban

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc thiet tach - hanh trinh cua chung ((vuong dan) OR (xuong dan)) ((toan cau) or (toan tap))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thiet tach - hanh trinh cua chung ((vuong dan) OR (xuong dan)) ((toan cau) OR (toan tap)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thiet tach - hanh trinh cua chung ((vuong dan) OR (xuong dan)) ((toan cau) or (toan tap))".
• Adding a wildcard symbol may retrieve word variants: hoc thiet tach - hanh trinh cua chung ((vuong dan) OR (xuong dan)) ((toan cau) or (toan tap))*.