Perhaps you should try some spelling variations:
thanh phan » thanh pho, thanh san, thanh toan
hieu van » hieu va, thien van, lieu va
phan cuu » phan cau, phan huu, phan cung
van cam » van nam, van lam, van cau
duc van » duc va, duc manh, duc phan
cuu tre » cua tre, cau tren, cau treo
nang xa » nang x, lang xa, mang xa
nang ma » tang ma, sang ma, nang cao
sac ky » cac ky, sai ky
tu sac » tu sach, tu cac, tu san

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sac ky ((nang xa) or (nang ma)) hoi. hieu van cam ((duc tan) or (duc van)) thanh phan cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky ((nang xa) OR (nang ma)) hoi. hieu van cam ((duc tan) OR (duc van)) thanh phan cuu tre.
• Adding a wildcard symbol may retrieve word variants: tu sac ky ((nang xa) or (nang ma)) hoi. hieu van cam ((duc tan) or (duc van)) thanh phan cuu tre*.