Perhaps you should try some spelling variations:
toc sach » doc sach, thuoc sach, nuoc sach
hoc sach » hoc sinh, hoc cac, hoc anh
van nang » van quang, van ban, van dong
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
cac luc » cau luc, coc luc, cac nuoc
va hanh » van hanh, va thanh, va danh
hanh de » hanh ve, hanh kem
cua tre » cua te, cuu tre, cua triet
luc va » duc va, tuc va, loc va
de cua » le cua, te cua, dieu cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((toc sach) OR (hoc sach)) van nang xa hoi. hieu va cac luc va hanh de cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) OR (hoc sach)) van nang xa hoi. hieu va cac luc va hanh de cua tre".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) OR (hoc sach)) van nang xa hoi. hieu va cac luc va hanh de cua tre*.