Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
cua tre » cuu tre, cua triet, dua tren
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
hanh di » hanh vi, hanh de, hang di
luc va » duc va, tuc va, loc va
cua te » cua tu
sach v » sach va, sach y, sach 2
xuc va » duc va, tuc va, xac va
va cam » va cham, va cac, va cao
v nang » va nang, vu nang, van nang

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