Perhaps you should try some spelling variations:
doanh hoa » doanh khoa, doanh hoan, danh hoa
sach hoi » sach doi, sach moi, cach thoi
cuu long » cuu cong, cuu tong, cuu nang
so doanh » so danh, su doanh, hoa doanh
van nhan » van phan, van thanh, danh nhan
nhan dan » phan dau, gian dan, nhan tai
tu sach » thu sach, su sach, te sach
hoi tap » hoi dap, hoc tap, hoi tai
long so » long soc, cong so, dong so
xa thai » ca thai, a thai, da thai
xa hai » xua hai, xa hoi, xa dai

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 tap, nghien cuu long so doanh hoa hoc ((xa hai) or (xa thai)) van nhan dan~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach hoi tap, nghien cuu long so doanh hoa hoc ((xa hai) OR (xa thai)) van nhan dan.
• Adding a wildcard symbol may retrieve word variants: tu sach hoi tap, nghien cuu long so doanh hoa hoc ((xa hai) or (xa thai)) van nhan dan*.