Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » thien van, lieu va, hieu ve
tinh hai » tinh thai, tinh chat, trinh han
nang ma » tang ma, sang ma, nang cao
hieu va » lieu va, hieu qua
va tinh » may tinh
cua tre » cuu tre, cua triet, dua tren
y nang » ky nang, ly nang, v nang
ma hoi » mai hoi, xa hoi, ma hoa
cua te » cua tu
du va » dau va, tu va, su va

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 ma hoi. ((hieu van) OR (hieu va)) cac du va tinh hai ((cua tre) OR (cua te))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach y nang ma hoi. ((hieu van) or (hieu va)) cac du va tinh hai ((cua tre) OR (cua te))~".
• Adding a wildcard symbol may retrieve word variants: toc sach y nang ma hoi. ((hieu van) or (hieu va)) cac du va tinh hai ((cua tre) OR (cua te))*.