Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
thu sach » tu sach, thuat sach, thu hoach
hieu van » hieu va, thien van, lieu va
van chat » cao chat
chat luc » chat xuc, chat lua, nhan luc
dinh dai » dinh dat, sinh dai, dinh tai
dinh dao » dinh dat, minh dao, dinh cao
cua tre » cua te, cuu tre, cua triet
luc va » duc va, tuc va, loc va

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((thu sach) or (thuoc sach)) ky nang x ho. hieu van chat luc va ((dinh dai) OR (dinh dao)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (thuoc sach)) ky nang x ho. hieu van chat luc va ((dinh dai) OR (dinh dao)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) or (thuoc sach)) ky nang x ho. hieu van chat luc va ((dinh dai) OR (dinh dao)) cua tre".
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (thuoc sach)) ky nang x ho. hieu van chat luc va ((dinh dai) OR (dinh dao)) cua tre*.