Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
van hanh » van thanh, ban hanh, van anh
cau phuc » cau truc, chau phu, huu phuc
sach ky » sac ky, sach y, sach ty
cua tre » cua te, cua triet, dua tren
cuu tre » cau tren, cau treo
cau luc » cau truc
hieu va » lieu va, hieu qua
x hoi » xa hoi, o hoi, x ho

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: hoc sach ky nang x hoi. hieu va ((cau luc) or (cau phuc)) van hanh vi ((cua tre) OR (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach ky nang x hoi. hieu va ((cau luc) OR (cau phuc)) van hanh vi ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sach ky nang x hoi. hieu va ((cau luc) or (cau phuc)) van hanh vi ((cua tre) OR (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: hoc sach ky nang x hoi. hieu va ((cau luc) or (cau phuc)) van hanh vi ((cua tre) OR (cuu tre))*.