Perhaps you should try some spelling variations:
nhan luc » nang luc
toc sach » hoc sach, doc sach, thuoc sach
van hanh » van thanh, ban hanh, van anh
hieu van » hieu va, thien van, lieu va
hanh le » thanh le, hanh ve, hanh de
hau luc » hau loc, cau luc, hieu luc
nang xa » nang x, lang xa, nang ma
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
le cua » ly cua

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 (toc sach)) y nang xa hoi. hieu van ((hau luc) or (nhan luc)) van hanh le cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) y nang xa hoi. hieu van ((hau luc) OR (nhan luc)) van hanh le cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) y nang xa hoi. hieu van ((hau luc) or (nhan luc)) van hanh le cua tre".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (toc sach)) y nang xa hoi. hieu van ((hau luc) or (nhan luc)) van hanh le cua tre*.