Perhaps you should try some spelling variations:
dau tren » dau tien, dat tren, dau tieng
hanh di » hanh vi, hanh de, hang di
va hanh » van hanh, va thanh, va danh
hieu va » lieu va, hieu qua
te sach » toc sach
ty nang » ky nang, ty hang, ly nang
cam tu » cam thu, nam tu, tam tu
dam tu » nam tu, tam tu, dam thuc
di dau » doi dau, bi dau, di du

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 ((ty nang) or (ty xang)) xa hoi. hieu va ((cam tu) or (dam tu)) va hanh di dau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ((ty nang) OR (ty xang)) xa hoi. hieu va ((cam tu) OR (dam tu)) va hanh di dau tren.
• Adding a wildcard symbol may retrieve word variants: te sach ((ty nang) or (ty xang)) xa hoi. hieu va ((cam tu) or (dam tu)) va hanh di dau tren*.