Perhaps you should try some spelling variations:
dau tren » dau tien, dat tren, dau tieng
cau tren » cu tren, ca tren, cau treo
va thanh » gia thanh, ban thanh, va tinh
sach ty » sach y, sach tu, sach thu
te sach » toc sach
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
ty nang » ky nang, ty xang, ty hang
va hanh » van hanh, va danh, ban hanh
cam tu » cam thu, nam tu, dam tu
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 ty nang xa hoi. hieu va cam tu ((va hanh) or (va thanh)) di ((cau tren) OR (dau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ty nang xa hoi. hieu va cam tu ((va hanh) OR (va thanh)) di ((cau tren) OR (dau tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ty nang xa hoi. hieu va cam tu ((va hanh) or (va thanh)) di ((cau tren) OR (dau tren))".
• Adding a wildcard symbol may retrieve word variants: te sach ty nang xa hoi. hieu va cam tu ((va hanh) or (va thanh)) di ((cau tren) OR (dau tren))*.