Perhaps you should try some spelling variations:
nghien thu » nghiem thuc, nghiep thuc, nghien cuu
hoa nhanh » hoc nhanh, hoa thanh, hoa khanh
nhanh hoa » nhanh hoan, thanh hoa, khanh hoa
sach dai » sach dao, sach bai, sach dat
cong hoa » dong hoa, dong hoc, hang hoa
nhan dan » phan dau, gian dan, nhan tai
tu sach » thu sach, su sach, te sach
dai hai » dai han, dai hoi, dai tai
hoc mai » hoc ma, hoc dai, hoc may
hoc bai » hoc dai, hoc giai
hoi ca » hoi cua, hoi cac, hoi cau

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 dai hai, nghien thu cong hoa nhanh hoa ((hoc mai) or (hoc bai)) hoi ca nhan dan~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach dai hai, nghien thu cong hoa nhanh hoa ((hoc mai) OR (hoc bai)) hoi ca nhan dan.
• Adding a wildcard symbol may retrieve word variants: tu sach dai hai, nghien thu cong hoa nhanh hoa ((hoc mai) or (hoc bai)) hoi ca nhan dan*.