Perhaps you should try some spelling variations:
nghien thu » nghiem thuc, nghiep thuc, nghien cuu
giang lang » gian lang, giang van, gian lan
sach duoc » sach nuoc, sach dao, sach dung
phan khoa » pham khoa, nhan khoa, phan hoa
sach hoi » sach doi, sach moi, cach thoi
cong hoc » dong hoc, cong hoa, cong coc
hoc phan » hoc dan, hoc pho
khoa hoc » hoa hoc
ca giang » cua giang, ha giang, ma giang
hoc xa » hoc ma
hoi ca » hoi cua, hoi cac, hoi cau

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 duoc) or (sach hoi)) tap, nghien thu cong hoc phan khoa hoc xa hoi ca giang lang~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach duoc) OR (sach hoi)) tap, nghien thu cong hoc phan khoa hoc xa hoi ca giang lang.
• Adding a wildcard symbol may retrieve word variants: tu ((sach duoc) or (sach hoi)) tap, nghien thu cong hoc phan khoa hoc xa hoi ca giang lang*.