Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
luc nhan » luc nhat, tue nhan, luc luan
hang ve » hang va, hanh ve, hang ke
cu nhan » ca nhan
te sach » toc sach
hieu va » lieu va, hieu qua
ty nang » ky nang, ty hang, ly nang
ve cau » ke cau, va cau, ve cac
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ((ty nang) OR (ty xang)) x hoi. hieu va cac ((luc nhan) or (cu nhan)) hang ve cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ((ty nang) OR (ty xang)) x hoi. hieu va cac ((luc nhan) OR (cu nhan)) hang ve cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ((ty nang) OR (ty xang)) x hoi. hieu va cac ((luc nhan) or (cu nhan)) hang ve cau tren".
• Adding a wildcard symbol may retrieve word variants: te sach ((ty nang) OR (ty xang)) x hoi. hieu va cac ((luc nhan) or (cu nhan)) hang ve cau tren*.