Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
qua cac » cua cac
luc va » duc va, tuc va
loc va » hoc va
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 ky nang x ho. hieu qua cac ((luc va) OR (loc va)) dan vi cau tren~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang x ho. hieu qua cac ((luc va) OR (loc va)) dan vi cau tren".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang x ho. hieu qua cac ((luc va) OR (loc va)) dan vi cau tren*.