Perhaps you should try some spelling variations:
sach hoi » sach moi, cach thoi, hoach hoi
sach doi » sach moi, sach dao, sach bai
cuu dong » cuu cong, cuu tong, cuu long
co thanh » cho thanh, o thanh, co tranh
cong hoc » dong hoc, cong hoa, cong coc
lang dau » hang dau, xang dau, nang dau
va lang » va nang, hoa lang
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 hoi) OR (sach doi)) dap, nghien cuu dong co thanh cong hoc xa hoi va lang dau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach hoi) OR (sach doi)) dap, nghien cuu dong co thanh cong hoc xa hoi va lang dau".
• Adding a wildcard symbol may retrieve word variants: tu ((sach hoi) OR (sach doi)) dap, nghien cuu dong co thanh cong hoc xa hoi va lang dau*.