Perhaps you should try some spelling variations:
thien van » thi van
nham thuc » nhan thuc, nam thuc, nham thu
toc sach » hoc sach, doc sach, thuoc sach
dinh dai » dinh dat, sinh dai, dinh dao
dua tren » dung tren
van nham » van nam, van nhan, van tham
cua tre » cua te, cua triet, cua thep
va dinh » van dinh, va kinh, va tinh
sach ky » sac ky, sach y, sach ty
thuc va » thuc vat, thuc dan, thuc day
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
cuu tre » cau tren, cau treo

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ky lang xa hoi. thien van nham thuc va dinh dai ((((cua tre) or (dua tren))) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky lang xa hoi. thien van nham thuc va dinh dai ((((cua tre) OR (dua tren))) OR (cuu tre)).
• Adding a wildcard symbol may retrieve word variants: toc sach ky lang xa hoi. thien van nham thuc va dinh dai ((((cua tre) or (dua tren))) or (cuu tre))*.