Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
ty nang » ky nang, ty xang, ly nang
ty hang » ly hang, ty xang, thi hang
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, va danh
hanh di » hanh vi, hanh de, hang di
cuu tre » cua tre, cau tren, cau treo
va cam » va cham, va cac, va cao
cam tu » cam thu, nam tu, dam tu
di cuu » di cau, di cua, dinh cuu

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ((ty nang) OR (ty hang)) xa hoi. hieu va cam tu va hanh di cuu tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ((ty nang) OR (ty hang)) xa hoi. hieu va cam tu va hanh di cuu tre".
• Adding a wildcard symbol may retrieve word variants: toc sach ((ty nang) OR (ty hang)) xa hoi. hieu va cam tu va hanh di cuu tre*.