Perhaps you should try some spelling variations:
khoa nganh » khoi nganh, hoc nganh
nganh hoa » thanh hoa, khanh hoa, danh hoa
sach hoc » sach hoi, mach hoc, sach duoc
cach hoc » cach thuc, cach thoi, dich hoc
cuu toan » cuu hoan, cua toan, huu toan
hoc mai » hoc ma, hoc dai, hoc bai
mai hoi » mai khoi, dai hoi, lai hoi
va nhan » van nhan, ca nhan, va phan
nhan va » nhan tai, nhan dan, nhan tao

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: te ((sach hoc) or (cach hoc)) tap, nghien cuu toan khoa nganh hoa hoc mai hoi va nhan va~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach hoc) OR (cach hoc)) tap, nghien cuu toan khoa nganh hoa hoc mai hoi va nhan va.
• Adding a wildcard symbol may retrieve word variants: te ((sach hoc) or (cach hoc)) tap, nghien cuu toan khoa nganh hoa hoc mai hoi va nhan va*.