Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
van dinh » van minh, van dich, xuan dinh
hieu van » hieu va, thien van, lieu va
va trien » va truyen, va thiet, va tuyen
cam duc » cam xuc, cao duc, pham duc
va dinh » va kinh, va tinh, vu dinh
van cam » van nam, van lam, van cau
y nang » ky nang, ly nang, v nang
o hoc » co hoc, mo hoc, so hoc
o hoi » co hoi, o hai, o hoa
cu va » cuu va, tu va, su va

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: thuat sach y nang ((o hoi) OR (o hoc)). hieu van cam duc ((van dinh) or (va dinh)) cu va trien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach y nang ((o hoi) OR (o hoc)). hieu van cam duc ((van dinh) OR (va dinh)) cu va trien.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat sach y nang ((o hoi) OR (o hoc)). hieu van cam duc ((van dinh) or (va dinh)) cu va trien".
• Adding a wildcard symbol may retrieve word variants: thuat sach y nang ((o hoi) OR (o hoc)). hieu van cam duc ((van dinh) or (va dinh)) cu va trien*.