Perhaps you should try some spelling variations:
canh trinh » canh tranh, hanh trinh, canh tinh
hien hanh » dieu hanh
trinh hoa » trinh do, trinh han
lang song » nang song, bang song, lang son
hoa lang » hoa dan, hoa van
song dan » song danh, song van, cong dan
phan cau » phan dau, phan cac, phan lap

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 hanh - canh trinh hoa lang song dan ((phan cau) or (phan tu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hien hanh - canh trinh hoa lang song dan ((phan cau) OR (phan tu))*.