Perhaps you should try some spelling variations:
va thanh » gia thanh, ban thanh, va tinh
sach ty » sach y, sach tu, sach thu
dan cua » dan ca, ban cua, dai cua
van cua » vang cua, ban cua, nan cua
cam luc » cam xuc, cau luc
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
ty nang » ky nang, ty xang, ty hang
co hai » co dai, co hoi, o hai
luc va » duc va, tuc va, loc va
va cam » va cham, va cac, va cao
o hoi » co hoi, o hoc, o hai

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 ((o hoi) or (co hai)). hieu va cam luc va thanh ((van cua) OR (dan cua)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang ((o hoi) OR (co hai)). hieu va cam luc va thanh ((van cua) OR (dan cua)) triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty nang ((o hoi) or (co hai)). hieu va cam luc va thanh ((van cua) OR (dan cua)) triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang ((o hoi) or (co hai)). hieu va cam luc va thanh ((van cua) OR (dan cua)) triet*.