Perhaps you should try some spelling variations:
thong cong » trong cong, tong cong, thong thong
canh trinh » canh tranh, hanh trinh, canh tinh
trinh vat » trinh van, trinh luat, sinh vat
vat thong » va thong, vat trong, mat thong
chi xanh » chi anh, chi danh, chi hanh
cong dan » cong san, cong tan, huong dan
phan cau » phan dau, phan cac, phan tu
hang dau » hang va, hang tai
doi chi » doi khi

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: doi chi xanh - canh trinh vat thong cong dan ((phan cau) OR (hang dau))~.
• Adding a wildcard symbol may retrieve word variants: doi chi xanh - canh trinh vat thong cong dan ((phan cau) or (hang dau))*.