Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu va » lieu va, hieu qua
cua tre » cua te, cua triet, dua tren
va hanh » van hanh, va thanh, va danh
cam luc » cam xuc, cau luc
cuu tre » cau tren, cau treo
ty nang » ky nang, ty xang, ty hang
luc va » duc va, tuc va, loc va
va cam » va cham, va cac, va cao

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sach) OR (toc sach)) ty nang x ho. hieu va cam luc va hanh vi ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ty nang x ho. hieu va cam luc va hanh vi ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) ty nang x ho. hieu va cam luc va hanh vi ((cua tre) or (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (toc sach)) ty nang x ho. hieu va cam luc va hanh vi ((cua tre) or (cuu tre))*.