Perhaps you should try some spelling variations:
nganh khung » nganh khong, nhanh hung
nghien chu » nghien cuu, nghiep cau, nghiep che
khung hoc » chung hoc, nhung hoc, thuong hoc
chu quang » chat quang, vu quang
quang hoc » quang hoi, quang huy, dung hoc
hoc nganh » hoc nhanh
mai khoi » mai khoa, tai khoa, cac khoi
nhan dan » gian dan, nhan tai
phan dau » phan tu, hang dau
sach hoc » cach hoc, sach hoi, mach hoc
hoc mai » hoc ma, hoc dai, hoc bai
khoi va » hoi va, khi va, choi va
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 quang hoc nganh khung hoc mai khoi va ((nhan dan) or (phan dau))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach hoc tap, nghien chu quang hoc nganh khung hoc mai khoi va ((nhan dan) OR (phan dau)).
• Adding a wildcard symbol may retrieve word variants: tu sach hoc tap, nghien chu quang hoc nganh khung hoc mai khoi va ((nhan dan) or (phan dau))*.