Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
danh vai » danh sai, doanh van, dang van
tham xuc » tham nuoc, tham thuc, pham duc
hieu van » hieu va, thien van, lieu va
van tham » van thanh, van tuan, van chat
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
danh va » doanh va, hanh va, anh va
tu sach » thu sach, su sach, te sach
xuc va » duc va, tuc va, luc va
o hoi » co hoi, o hoc, o hai
x hoi » xa hoi, x ho, 5 hoi

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 ty nang ((x hoi) OR (o hoi)). hieu van tham xuc va ((danh vai) or (danh va)) cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang ((x hoi) OR (o hoi)). hieu van tham xuc va ((danh vai) OR (danh va)) cau tren*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty nang ((x hoi) OR (o hoi)). hieu van tham xuc va ((danh vai) or (danh va)) cau tren*".