Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
hieu van » hieu va, thien van, lieu va
thanh vi » hanh vi, thanh va, thanh ve
nam luc » nang luc, nhan luc, nam thuc
cuu tre » cau tren, cau treo
luc van » luoc van, luu van, duc van
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
xay hoi » tay hoi, cay phoi, gay thoi
ky dang » ky nang, ky danh
cua tre » cua te, cua triet, dua tren

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