Perhaps you should try some spelling variations:
hanh trinh » canh tranh, hanh chinh
nganh cong » nhanh chong, thanh cong
trinh cac » trinh cau, trinh chat, trinh chao
cac nganh » hoc nganh
ho chieu » theo chieu, hoc thieu, doi chieu
tam toan » tap toan, tam than, pham toan
bai toan » bai tap
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: ((ho chieu) or (doi chi)) tinh - hanh trinh cac nganh cong ((tam toan) or (bai toan)) tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((ho chieu) OR (doi chi)) tinh - hanh trinh cac nganh cong ((tam toan) OR (bai toan)) tap.
• Adding a wildcard symbol may retrieve word variants: ((ho chieu) or (doi chi)) tinh - hanh trinh cac nganh cong ((tam toan) or (bai toan)) tap*.