Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
dang xay » dang van, van xay
nam thuc » nam thuoc, am thuc, nam thu
tu sach » su sach, te sach, tu cach
cua tre » cuu tre, cua triet, dua tren
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
hieu le » hieu ve, hieu he, hieu ly
xay hoi » xa hoi, tay hoi, cay phoi
ky dang » ky nang, ky danh
le nam » ly nam, he nam, le na
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (thu sach)) ky dang xay hoi. hieu le nam thuc va hanh vi ((cua tre) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ky dang xay hoi. hieu le nam thuc va hanh vi ((cua tre) OR (cua te)).
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) ky dang xay hoi. hieu le nam thuc va hanh vi ((cua tre) or (cua te))*.