Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
nhan luc » nang luc
van hanh » van thanh, ban hanh, van anh
cao hoi » cau hoi, co hoi, cao hoc
nam luc » nang luc, nam thuc, nam duoc
cuu tre » cua tre, cau tren, cau treo
y nang » ky nang, ly nang, v nang
vi cuu » vi luu, vinh cuu

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 cao hoi. hieu van ((nam luc) or (nhan luc)) van hanh vi cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) y nang cao hoi. hieu van ((nam luc) OR (nhan luc)) van hanh vi cuu tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) y nang cao hoi. hieu van ((nam luc) or (nhan luc)) van hanh vi cuu tre*".