Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
dinh te » kinh te, dinh ve, dinh tu
cam tuc » cam xuc, cam tu, nam thuc
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
xu dang » su dang, vu dang, xo dang
xu lang » cu lang, tu lang, xu quang
tuc va » thuc va, truc va, tuc xa
ve cam » ve cham, ve cac, va cam

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 ((xu lang) OR (xu dang)) xa hoi. hieu ve cam tuc va ((dinh te) or (dich te)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((xu lang) OR (xu dang)) xa hoi. hieu ve cam tuc va ((dinh te) OR (dich te)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ((xu lang) OR (xu dang)) xa hoi. hieu ve cam tuc va ((dinh te) or (dich te)) cua tre".
• Adding a wildcard symbol may retrieve word variants: toc sach ((xu lang) OR (xu dang)) xa hoi. hieu ve cam tuc va ((dinh te) or (dich te)) cua tre*.