Perhaps you should try some spelling variations:
cua tren » dua tren, ca tren, cua tre
nam thuc » nam thuoc, am thuc, nam thu
hieu van » hieu va, thien van, lieu va
hang vi » hanh vi, hang di, khang voi
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nam luc » nang luc, nhan luc, nam duoc
tang xa » trang xa, tang ma, lang xa
ky tang » ky nang, ky dang, kho tang

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

• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky tang xa hoi. hieu van ((nam luc) OR (nam thuc)) va ((hang vi) OR (hang va)) cua tren~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky tang xa hoi. hieu van ((nam luc) or (nam thuc)) va ((hang vi) OR (hang va)) cua tren~".
• Adding a wildcard symbol may retrieve word variants: tu sach ky tang xa hoi. hieu van ((nam luc) or (nam thuc)) va ((hang vi) OR (hang va)) cua tren*.