Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
hanh tai » thanh tai, hang tai, han tai
van hanh » van thanh, ban hanh, van anh
cam luc » cam xuc, cau luc
cua tre » cua te, cuu tre, cua triet
luc van » luoc van, luu van, duc van
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
hieu ve » hieu va, hieu van
ty nang » ky nang, ty xang, ty hang
ve cam » ve cham, ve cac, va cam
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 ve cam luc van hanh tai ((cua tre) or (su triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang ((x hoi) OR (o hoi)). hieu ve cam luc van hanh tai ((cua tre) OR (su triet))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty nang ((x hoi) OR (o hoi)). hieu ve cam luc van hanh tai ((cua tre) or (su triet))*".