Perhaps you should try some spelling variations:
sach doi » sach hoi, sach moi, sach dao
cuu dong » cuu tong, cuu long, luu dong
cuu cong » cua cong, thu cong, cac cong
luc ngan » luc nganh, luc nhan, luat ngan
ngan hoa » nganh hoa, nhan hoa, nganh khoa
cau nhan » chau nhan, ca nhan, cu nhan
nhan dan » phan dau, gian dan, nhan tai
tu sach » thu sach, su sach, te sach
doi tac » dong tac
hoi cau » hoi chu, hoc cau, hoa cau
hoc xa » hoc ma

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 doi tac, nghien ((cuu dong) or (cuu cong)) luc ngan hoa hoc xa hoi cau nhan dan~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach doi tac, nghien ((cuu dong) OR (cuu cong)) luc ngan hoa hoc xa hoi cau nhan dan.
• Adding a wildcard symbol may retrieve word variants: tu sach doi tac, nghien ((cuu dong) or (cuu cong)) luc ngan hoa hoc xa hoi cau nhan dan*.