Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
hanh lai » hanh lam, hanh tai, thanh lap
van hanh » van thanh, ban hanh, van anh
tang van » dang van, hoang van, trong van
hieu van » hieu va, thien van, lieu va
te sach » toc sach
cau luc » cau truc, cau phuc
lai cua » dai cua, hai cua, lai chau
cau duc » cao duc, chu duc, cau truc
van hoc » van hoa
ky tang » ky nang, ky dang, kho tang
cua tre » cua te, cuu tre, cua triet

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

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