Perhaps you should try some spelling variations:
thanh chong » thanh chuong, thanh cong, nhanh chong
nghien cac » nghiep cach, nghien cuu, nghiep cay
chong dich » luong dich, hang dich
hoa thanh » hoan thanh, ha thanh, hoc thanh
sach hoc » cach hoc, sach hoi, mach hoc
cac cong » cua cong
cong hoa » dong hoa, dong hoc, hang hoa
dich can » dich han, dich ran, lich can
phan dau » phan tu, hang dau
vu sach » vu bach, su sach, vu khach
can hoi » cau hoi, can ho, dan hoi
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: vu sach hoc tap, nghien cac cong hoa thanh chong dich can hoi ca ((phan dau) or (hang va))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach hoc tap, nghien cac cong hoa thanh chong dich can hoi ca ((phan dau) OR (hang va)).
• Adding a wildcard symbol may retrieve word variants: vu sach hoc tap, nghien cac cong hoa thanh chong dich can hoi ca ((phan dau) or (hang va))*.