Perhaps you should try some spelling variations:
khong cong » thong cong, chong cong, khong con
khong cang » thong cong, hong bang, khong dung
theo phap » thi phap
phap tinh » phap sinh, phap tieng, phap tang
thang ca » thang cua, tang ca, thang va
san toan » van toan, dan toan, manh toan
toan cau » toan cao, toan ban, toan tap
hang ca » hang va, nang cao, hang tai

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

• If you are trying to use Boolean operators, they must be ALL CAPS: theo phap tinh - hung ((thang ca) OR (hang ca)) ((khong cong) OR (khong cang)) san toan cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo phap tinh - hung ((thang ca) or (hang ca)) ((khong cong) OR (khong cang)) san toan cau~".
• Adding a wildcard symbol may retrieve word variants: theo phap tinh - hung ((thang ca) or (hang ca)) ((khong cong) OR (khong cang)) san toan cau*.