Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hieu va » lieu va, hieu qua
cac tuc » cac toc, cac tu, cac nuoc
cac tac » cac toc, cac bac, cac dac
dinh vi » dinh ve, dinh viet, dinh tri
danh di » danh du, xanh di, danh dien
cuu tre » cua tre, cau tren, cau treo
y nang » ky nang, ly nang, v nang

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 y nang x ho. hieu va ((cac tuc) OR (cac tac)) va ((dinh vi) or (danh di)) cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach y nang x ho. hieu va ((cac tuc) OR (cac tac)) va ((dinh vi) OR (danh di)) cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach y nang x ho. hieu va ((cac tuc) OR (cac tac)) va ((dinh vi) or (danh di)) cuu tre".
• Adding a wildcard symbol may retrieve word variants: thu sach y nang x ho. hieu va ((cac tuc) OR (cac tac)) va ((dinh vi) or (danh di)) cuu tre*.