Perhaps you should try some spelling variations:
nhanh han » nhanh hoan, hanh han, nhanh hai
sach hoc » cach hoc, sach hoi, mach hoc
cuu dong » cuu cong, cuu tong, cuu long
dong hoc » dong co, dong luc
nhanh ha » thanh hoa, thanh hai, khanh hoa
dac nhan » cac nhan, danh nhan, ca nhan
nhan dan » phan dau, gian dan, nhan tai
so sach » so sanh, bo sach, co sach
hoi dac » hoi dap, hoi dan, hoi dat
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: so sach hoc tap, nghien cuu dong hoc ((nhanh ha) or (nhanh han)) hoc xa hoi dac nhan dan~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach hoc tap, nghien cuu dong hoc ((nhanh ha) OR (nhanh han)) hoc xa hoi dac nhan dan.
• Adding a wildcard symbol may retrieve word variants: so sach hoc tap, nghien cuu dong hoc ((nhanh ha) or (nhanh han)) hoc xa hoi dac nhan dan*.