Perhaps you should try some spelling variations:
thien van » thi van
cau tren » cu tren, dau tren, ca tren
tinh vai » tinh hai, tinh bai, tinh lai
tinh va » tich va, trinh van, trinh vat
sach ky » sac ky, sach y, sach ty
te sach » toc sach
van cam » van nam, van lam, van cau
cam tu » cam thu, nam tu, dam tu
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: te sach ky nang ((x hoi) OR (o hoi)). thien van cam tu va ((tinh vai) or (tinh va)) cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky nang ((x hoi) OR (o hoi)). thien van cam tu va ((tinh vai) OR (tinh va)) cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky nang ((x hoi) OR (o hoi)). thien van cam tu va ((tinh vai) or (tinh va)) cau tren".
• Adding a wildcard symbol may retrieve word variants: te sach ky nang ((x hoi) OR (o hoi)). thien van cam tu va ((tinh vai) or (tinh va)) cau tren*.