Perhaps you should try some spelling variations:
toc sach » doc sach, thuoc sach, nuoc sach
hoc sach » hoc sinh, hoc cac, hoc anh
nang xa » nang x, lang xa, nang ma
cao luc » bao luc, cao duc, cao suc
cua tre » cua te, cuu tre, cua triet
v nang » va nang, vu nang, van nang
va cao » va cac, va co, va dao
luc va » duc va, tuc va, loc va
dan di » danh di, dan da, dan li
dan de » dan den, dang de, van de

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