Perhaps you should try some spelling variations:
nghien chu » nghien cuu, nghiep cau, nghiep che
thuong hoc » truong hoc, tuong hoc, thuong ho
khung hoc » chung hoc, nhung hoc, trung hoc
hoc nganh » hoc nhanh
mai khoi » mai khoa, tai khoa, cac khoi
nhan dan » phan dau, gian dan, nhan tai
sach hoc » cach hoc, sach hoi, mach hoc
tuan hoc » toan hoc, luan hoc, than hoc
chu tuan » chu xuan, thu tuan, chu quang
khoi va » hoi va, khi va, choi va
va nhan » van nhan, ca nhan, va phan
tu sach » thu sach, su sach, te sach

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 chu tuan hoc nganh ((khung hoc) OR (thuong hoc)) mai khoi va nhan dan~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach hoc tap, nghien chu tuan hoc nganh ((khung hoc) OR (thuong hoc)) mai khoi va nhan dan".
• Adding a wildcard symbol may retrieve word variants: tu sach hoc tap, nghien chu tuan hoc nganh ((khung hoc) OR (thuong hoc)) mai khoi va nhan dan*.