Perhaps you should try some spelling variations:
canh trinh » canh tranh, hanh trinh, canh tinh
phung cong » nhung cong, phong cong, nhung chong
hoc trieu » hoc thieu, hoc tieu, hoc dieu
trinh vat » trinh van, trinh luat, sinh vat
vat phung » van phung, vat dung, vat khong
cong san » cong tac
pham cau » phan cau, pham ca, pha cau
pham can » pham van, pham lan, pham ca

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc trieu tinh - canh trinh vat phung cong san ((pham cau) or (pham can))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc trieu tinh - canh trinh vat phung cong san ((pham cau) OR (pham can)).
• Adding a wildcard symbol may retrieve word variants: hoc trieu tinh - canh trinh vat phung cong san ((pham cau) or (pham can))*.