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
dinh vi » dinh ve, dinh viet, dinh tri
va dinh » van dinh, va kinh, va tinh
cam luc » cam xuc, cau luc
cuu tre » cua tre, cau tren, cau treo
hieu ve » hieu va
dang xa » dang xay, lang xa, dang ha
ky dang » ky nang, ky danh
luc va » duc va, tuc va, loc va
vi cuu » vi luu, vinh cuu

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 dang xa hoi. ((hieu ve) or (hieu van)) cam luc va dinh vi cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (thuoc sach)) ky dang xa hoi. ((hieu ve) OR (hieu van)) cam luc va dinh vi cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) OR (thuoc sach)) ky dang xa hoi. ((hieu ve) or (hieu van)) cam luc va dinh vi cuu tre".
• Adding a wildcard symbol may retrieve word variants: ((thu sach) OR (thuoc sach)) ky dang xa hoi. ((hieu ve) or (hieu van)) cam luc va dinh vi cuu tre*.