Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
cham xuc » cam xuc, chat xuc, cham soc
dan dai » dat dai, can dai, dan dat
va cham » va chat, va tham
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, xa hoi, me hoi
y nang » ky nang, ly nang, v nang
xuc va » duc va, tuc va, luc va
va dan » ca dan, va dao, va dau

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sach) or (toc sach)) y nang ((ma hoi) OR (ma hoa)). hieu va cham xuc va dan dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) y nang ((ma hoi) OR (ma hoa)). hieu va cham xuc va dan dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (toc sach)) y nang ((ma hoi) OR (ma hoa)). hieu va cham xuc va dan dai cua tre".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) y nang ((ma hoi) OR (ma hoa)). hieu va cham xuc va dan dai cua tre*.