Perhaps you should try some spelling variations:
trinh toan » tinh toan, thanh toan, trinh quan
hien tinh » khien tinh, thien tinh, bien tinh
trinh han » trinh quan
tong cong » trong cong, cong cong, dung cong
cong dan » cong san, cong tan, huong dan
than cau » toan cau, than cap, thanh chau
phan cau » phan dau, phan cac, phan tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc hien tinh - canh ((trinh han) or (trinh toan)) tong cong dan ((than cau) or (phan cau))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hien tinh - canh ((trinh han) OR (trinh toan)) tong cong dan ((than cau) OR (phan cau)).
• Adding a wildcard symbol may retrieve word variants: hoc hien tinh - canh ((trinh han) or (trinh toan)) tong cong dan ((than cau) or (phan cau))*.