Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
van hanh » van thanh, ban hanh, van anh
xuc van » duc van, luc van, vuc van
sach ty » sach y, sach tu, sach thu
tu sach » thu sach, su sach, te sach
ty nang » ky nang, ty xang, ty hang
ve cac » va cac, vien cac
kem va » kiem va, kiem van
ve cam » ve cham, va cam, ve cai
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) or (ve cac)) xuc van hanh kem va 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) OR (ve cac)) xuc van hanh kem va 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) or (ve cac)) xuc van hanh kem va triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang ((x hoi) OR (o hoi)). hieu ((ve cam) or (ve cac)) xuc van hanh kem va triet*.