Perhaps you should try some spelling variations:
dac khanh » dat khanh, dan khanh, duc khanh
phong hoc » phong ho, thong hoc, phuong hoa
sach hoi » sach doi, cach thoi, hoach hoi
sach moi » sach doi, bach mai, sach bai
cuu cong » cua cong, thu cong, cac cong
cong dac » cong tac, cong dan, cong cac
nhan va » nhan tai, nhan dan, nhan tao
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 hoi) OR (sach moi)) tap, nghien cuu cong dac khanh phong hoc xa hoi ca nhan va~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach hoi) OR (sach moi)) tap, nghien cuu cong dac khanh phong hoc xa hoi ca nhan va".
• Adding a wildcard symbol may retrieve word variants: tu ((sach hoi) OR (sach moi)) tap, nghien cuu cong dac khanh phong hoc xa hoi ca nhan va*.