Perhaps you should try some spelling variations:
toc sach » hoc sach, thuoc sach, nuoc sach
doc sach » hoc sach, nuoc sach, dac sac
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
cac xuc » cam xuc, cac nuoc, chat xuc
va hanh » van hanh, va thanh, va danh
cua tre » cuu tre, cua triet, dua tren
v nang » va nang, vu nang, van nang
xuc va » duc va, tuc va, luc va
cua te » cua tu

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