Perhaps you should try some spelling variations:
thien hach » thien thanh, hien hanh
hoc thien » hoc hien, hoc thieu, hoc thiet
hanh tinh » hanh trinh, nhanh tinh, thanh tinh
cua thong » cua thuong, cua khong, cua tong
tinh cua » trinh cua, sinh cua, tinh chat
toan can » toan ban, toan cao, toan cau
tac can » tac van, tac quan, tac vang

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 tinh cua thong thong ((tac can) or (toan can)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thien hach - hanh tinh cua thong thong ((tac can) OR (toan can)) cau.
• Adding a wildcard symbol may retrieve word variants: hoc thien hach - hanh tinh cua thong thong ((tac can) or (toan can)) cau*.