Perhaps you should try some spelling variations:
hien manh » hien hanh, tien manh, hieu manh
trinh vat » trinh van, trinh luat, sinh vat
lang song » nang song, bang song, lang son
trinh va » trinh van, trinh ve, trinh vi
song dan » song danh, song van, cong dan
dan phan » doan phan, dan chan, van phan
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 manh - canh ((trinh va) or (trinh vat)) lang song dan phan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hien manh - canh ((trinh va) OR (trinh vat)) lang song dan phan cau.
• Adding a wildcard symbol may retrieve word variants: hoc hien manh - canh ((trinh va) or (trinh vat)) lang song dan phan cau*.