Perhaps you should try some spelling variations:
doc sach » hoc sach, toc sach, nuoc sach
cau tren » cu tren, dau tren, ca tren
hieu va » lieu va, hieu qua
va danh » va dinh, va dan, va hanh
danh vi » hanh vi, dinh vi, danh di
y nang » ky nang, ly nang, may nang
v nang » va nang, vu nang, van nang
va cam » va cham, va cac, va cao
xuc va » duc va, tuc va, luc va
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: doc sach ((y nang) OR (v nang)) ma hoa. hieu va cam xuc va danh vi cau tren~.
• Adding a wildcard symbol may retrieve word variants: doc sach ((y nang) or (v nang)) ma hoa. hieu va cam xuc va danh vi cau tren*.