Perhaps you should try some spelling variations:
nhanh hoan » thanh hoang, thanh hoa, khanh hoa
nhanh hoa » thanh hoa, khanh hoa, nhanh ha
sach doi » sach hoi, sach moi, sach dao
cuu cong » cua cong, thu cong, cac cong
cong hoc » dong hoc, cong hoa, cong coc
tu sach » thu sach, su sach, te sach
doi tap » doi tac, doi dap, doi tai
hoi van » hoi va, hoi dan, hai van
van von » vay von, van van, van dong
hoc xa » hoc ma

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach doi tap, nghien cuu cong hoc ((nhanh hoa) or (nhanh hoan)) hoc xa hoi van von tai~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach doi tap, nghien cuu cong hoc ((nhanh hoa) OR (nhanh hoan)) hoc xa hoi van von tai.
• Adding a wildcard symbol may retrieve word variants: tu sach doi tap, nghien cuu cong hoc ((nhanh hoa) or (nhanh hoan)) hoc xa hoi van von tai*.