Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
hieu van » hieu va, thien van, lieu va
tinh hai » tinh thai, tinh chat, trinh han
tinh dai » trinh dai, tinh da, tinh doi
cham loc » cham soc, chon loc, cham o
hieu ve » hieu va
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
cua tre » cua te, cuu tre, cua triet
loc va » hoc va, luc va

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

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