Perhaps you should try some spelling variations:
lang van » dang van, tang van, hoang van
nam thuc » nam thuoc, am thuc, nam thu
vu sach » vu bach, su sach, vu khach
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
hieu va » lieu va, hieu qua
sach ky » sac ky, sach y, sach ty
lang ha » long ha
lang xa » dang xay
cua tre » cua te, cuu tre, cua triet
va nam » van nam, ha nam, va nay
vi cua » vai cua, di cua

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 ky ((((lang xa) OR (lang ha))) or (lang van)) hoi. hieu va nam thuc va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky ((((lang xa) OR (lang ha))) OR (lang van)) hoi. hieu va nam thuc va hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ky ((((lang xa) OR (lang ha))) or (lang van)) hoi. hieu va nam thuc va hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: vu sach ky ((((lang xa) OR (lang ha))) or (lang van)) hoi. hieu va nam thuc va hanh vi cua tre*.