Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, su sach, te sach
van cam » van nam, van lam, van cau
cam luc » cam xuc, cau luc
luc van » luoc van, luu van, duc van
doi cua » dai cua, hoi cua, dong cua
y nang » ky nang, ly nang, v nang
di cua » dai cua, de cua, do cua
x hoi » xa hoi, o hoi, 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 y nang ((x hoi) or (x ho)). hieu van cam luc van hanh ((di cua) or (doi cua)) vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang ((x hoi) OR (x ho)). hieu van cam luc van hanh ((di cua) OR (doi cua)) vat.
• Adding a wildcard symbol may retrieve word variants: tu sach y nang ((x hoi) or (x ho)). hieu van cam luc van hanh ((di cua) or (doi cua)) vat*.