Perhaps you should try some spelling variations:
nghien cac » nghiep cach, nghien cuu, nghiep cay
phan chong » phan hong, phap chong, phan chung
phan cong » thanh cong
giao dan » gian dan, giao dat, giao dien
dich can » dich han, dich ran, lich can
cac cong » cua cong
cong hoc » dong hoc, cong hoa, cong coc
sach hoc » cach hoc, sach hoi, mach hoc
ca giao » cua giao, co giao, va giao
su sach » so sach, vu sach
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: su sach hoc tap, nghien cac cong hoc ((phan chong) OR (phan cong)) dich can hoi ca giao dan~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach hoc tap, nghien cac cong hoc ((phan chong) OR (phan cong)) dich can hoi ca giao dan".
• Adding a wildcard symbol may retrieve word variants: su sach hoc tap, nghien cac cong hoc ((phan chong) OR (phan cong)) dich can hoi ca giao dan*.