Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
van cam » van nam, van lam, van cau
cam duc » cam xuc, cao duc, pham duc
va hanh » van hanh, va thanh, va danh
y nang » ky nang, ly nang, may nang
v nang » va nang, vu nang, van nang
do cua » doi cua, co cua, dong cua
de cua » le cua, te cua, dieu cua
x hoi » xa hoi, o hoi, x ho

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) or (v nang)) x hoi. hieu van cam duc va hanh ((do cua) or (de cua)) vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((y nang) OR (v nang)) x hoi. hieu van cam duc va hanh ((do cua) OR (de cua)) vat.
• Adding a wildcard symbol may retrieve word variants: tu sach ((y nang) or (v nang)) x hoi. hieu van cam duc va hanh ((do cua) or (de cua)) vat*.