Perhaps you should try some spelling variations:
khong thuoc » khang thuoc, hong phuoc, dong thuoc
hoc nhanh » hoc phan
sach hoc » cach hoc, sach hoi, mach hoc
cuu cong » cua cong, thu cong, cac cong
thuoc ma » hoc ma, duoc ma
nhan dan » phan dau, gian dan, nhan tai
tu sach » thu sach, su sach, te sach
va nhan » van nhan, ca nhan, va phan
ma hoi » mai hoi, xa hoi, ma hoa

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 hoc tap, nghien cuu cong ((hoc nhanh) or (hoc nganh)) khong thuoc ma hoi va nhan dan~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach hoc tap, nghien cuu cong ((hoc nhanh) OR (hoc nganh)) khong thuoc ma hoi va nhan dan.
• Adding a wildcard symbol may retrieve word variants: tu sach hoc tap, nghien cuu cong ((hoc nhanh) or (hoc nganh)) khong thuoc ma hoi va nhan dan*.