Perhaps you should try some spelling variations:
nhan luc » nang luc
vanh tai » van tai, hanh tai, anh tai
vanh dai » van dai, lanh dao, va dai
tu sach » thu sach, su sach, te sach
cuu tre » cua tre, cau tren, cau treo
sach ky » sac ky, sach y, sach ty
va nhan » van nhan, ca nhan, va phan
hieu va » lieu va, hieu qua
dang xa » dang xay, lang xa, dang ha
ky dang » ky nang, ky danh
luc va » duc va, tuc va, loc va

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 dang xa hoi. hieu va nhan luc va ((((vanh dai) OR (van dao))) or (vanh tai)) cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky dang xa hoi. hieu va nhan luc va ((((vanh dai) OR (van dao))) OR (vanh tai)) cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky dang xa hoi. hieu va nhan luc va ((((vanh dai) OR (van dao))) or (vanh tai)) cuu tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky dang xa hoi. hieu va nhan luc va ((((vanh dai) OR (van dao))) or (vanh tai)) cuu tre*.