Perhaps you should try some spelling variations:
khanh vai » khanh van, hanh vi, hanh va
dau tien » van tien
dau tren » dat tren, dau tieng, dau trong
toc sach » hoc sach, doc sach, thuoc sach
xa khanh » xa thanh, van khanh, dat khanh
nam tuc » nam thuc, nam truc, nam tu
nang ma » tang ma, sang ma, nang cao
hieu va » lieu va, hieu qua
va nam » van nam, ha nam, va nay
ma hoi » mai hoi, xa hoi, ma hoa

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)) ky nang ma hoi. hieu va nam tuc xa khanh vai ((dau tren) OR (dau tien))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ky nang ma hoi. hieu va nam tuc xa khanh vai ((dau tren) OR (dau tien)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (toc sach)) ky nang ma hoi. hieu va nam tuc xa khanh vai ((dau tren) OR (dau tien))".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) ky nang ma hoi. hieu va nam tuc xa khanh vai ((dau tren) OR (dau tien))*.