Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu va » hieu qua
loc va » luc va
dan vi » doan vi, don vi, dan va
vi cua » vai cua, di cua
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ky nang xa hoi. ((hieu va) or (lieu va)) cac ((loc va) OR (hoc va)) dan vi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky nang xa hoi. ((hieu va) OR (lieu va)) cac ((loc va) OR (hoc va)) dan vi cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky nang xa hoi. ((hieu va) or (lieu va)) cac ((loc va) OR (hoc va)) dan vi cua te".
• Adding a wildcard symbol may retrieve word variants: thu sach ky nang xa hoi. ((hieu va) or (lieu va)) cac ((loc va) OR (hoc va)) dan vi cua te*.