Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
bao thuc » cao thuoc, am thuc, va thuc
dua tren » dung tren
va hanh » van hanh, va thanh, va danh
sach ky » sac ky, sach y, sach ty
thuc va » thuc vat, thuc dan, thuc day
hieu va » lieu va, hieu qua
tang ma » mang may, tang van
ky tang » ky nang, ky dang, kho tang
cuu tre » cua tre, cau tren, cau treo
va bao » va bai
ma hoi » mai hoi, xa hoi, ma hoa
cua tu » cua tuc, cua su, cua cu

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: thu sach ky tang ma hoi. hieu va bao thuc va hanh vi ((((dua tren) OR (cua tu))) OR (cuu tre))~.
• Adding a wildcard symbol may retrieve word variants: thu sach ky tang ma hoi. hieu va bao thuc va hanh vi ((((dua tren) or (cua tu))) or (cuu tre))*.