Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
cau treo » cau theo, cau tren, cau triet
vu nang » vuc nang, va nang, vu dang
va danh » va dinh, va hanh, dia danh
van cam » van nam, van lam, van cau
ma hoi » mai hoi, xa hoi, ma hoa
y nang » ky nang, ly nang, v nang
va dan » ca dan, va dao, va dau
vi cau » va cau, ve cau, di cau

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

• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((y nang) OR (vu nang)) ma hoi. hieu van cam xuc ((va danh) OR (va dan)) vi cau treo~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ((y nang) or (vu nang)) ma hoi. hieu van cam xuc ((va danh) OR (va dan)) vi cau treo~".
• Adding a wildcard symbol may retrieve word variants: toc sach ((y nang) or (vu nang)) ma hoi. hieu van cam xuc ((va danh) OR (va dan)) vi cau treo*.