Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
tu sach » thu sach, su sach, tu cach
te sach » toc sach
qua cac » cua cac
cac luc » cau luc, coc luc, cac nuoc
luc va » duc va, tuc va, loc va
va dan » ca dan, va dao, va dau
dan vi » doan vi, don vi, dan va
vi cau » va cau, ve cau, di cau

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) OR (te sach)) ky nang x ho. hieu qua cac luc va dan vi cau tren~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (te sach)) ky nang x ho. hieu qua cac luc va dan vi cau tren".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (te sach)) ky nang x ho. hieu qua cac luc va dan vi cau tren*.