Perhaps you should try some spelling variations:
sach nuoc » sach duoc, cac nuoc, bach tuoc
hanh hai » thanh hai, nhanh hai, hang hai
dua tren » dung tren
vu sach » vu bach, su sach, vu khach
hieu va » lieu va
va hanh » van hanh, va thanh, va danh
y nang » ky nang, ly nang, v nang
cua te » cua tu
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: vu sach y nang x hoi. ((hieu va) or (hieu qua)) sach nuoc va hanh hai ((dua tren) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach y nang x hoi. ((hieu va) OR (hieu qua)) sach nuoc va hanh hai ((dua tren) OR (cua te)).
• Adding a wildcard symbol may retrieve word variants: vu sach y nang x hoi. ((hieu va) or (hieu qua)) sach nuoc va hanh hai ((dua tren) or (cua te))*.