Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » thien van, lieu va, hieu ve
cua viet » ca viet, hoa viet, cua vat
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, va danh
hanh ve » hanh vi, hanh va, hanh kem
y nang » ky nang, ly nang, v nang
xuc va » duc va, tuc va, luc va
ve cua » le cua, de cua, te 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: toc sach y nang x hoi. ((hieu van) or (hieu va)) cam xuc va hanh ve cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y nang x hoi. ((hieu van) OR (hieu va)) cam xuc va hanh ve cua viet.
• Adding a wildcard symbol may retrieve word variants: toc sach y nang x hoi. ((hieu van) or (hieu va)) cam xuc va hanh ve cua viet*.