Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
van hanh » van thanh, ban hanh, van anh
van cam » van nam, van lam, van cau
xuc van » duc van, luc van, vuc van
y nang » ky nang, ly nang, v nang
di cua » doi 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: toc sach y nang ((x hoi) or (x ho)). hieu van cam xuc van hanh ((di cua) or (dai cua)) viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y nang ((x hoi) OR (x ho)). hieu van cam xuc van hanh ((di cua) OR (dai cua)) viet.
• Adding a wildcard symbol may retrieve word variants: toc sach y nang ((x hoi) or (x ho)). hieu van cam xuc van hanh ((di cua) or (dai cua)) viet*.