Perhaps you should try some spelling variations:
nganh khong » nganh cong, nhanh chong, nganh nong
khong thuoc » khang thuoc, hong phuoc, dong thuoc
hoc nganh » hoc nhanh
sach hoc » cach hoc, mach hoc, sach duoc
sach hoi » sach doi, sach moi, cach thoi
cuu toan » cuu hoan, cua toan, huu toan
toan hoc » toan khoa, van hoc, hoa hoc
thuoc la » thuoc ma, thuoc va, thuoc tai
va nhan » van nhan, ca nhan, va phan
nhan va » nhan tai, nhan dan, nhan tao
la hoi » lai hoi, xa hoi, le hoi

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