Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
ve triet » va trien, su triet
tang xa » trang xa, tang ma, tang ha
lang xa » lang ha, dang xay, lang van
sach ky » sac ky, sach y, sach ty
thuc va » thuc vat, thuc dan, thuc day
dinh ke » dinh ket, dinh ve, dinh le
xuc va » duc va, tuc va, luc va
va cam » va cham, va cac, va cao
ke ve » ke va, ke he, de ve

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 ((tang xa) or (lang xa)) hoi. lieu va cam ((xuc va) or (thuc va)) dinh ke ve triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky ((tang xa) OR (lang xa)) hoi. lieu va cam ((xuc va) OR (thuc va)) dinh ke ve triet.
• Adding a wildcard symbol may retrieve word variants: toc sach ky ((tang xa) or (lang xa)) hoi. lieu va cam ((xuc va) or (thuc va)) dinh ke ve triet*.