Perhaps you should try some spelling variations:
nang mai » nang ma, nang tai, lang mai
te sach » toc sach
sach ky » sac ky, sach y, sach ty
mai hoi » mai khoi, dai hoi, lai hoi
hieu va » lieu va, hieu qua
va cham » va chat, va tham
dau cua » day cua, cau cua, dan cua
soc va » loc va, doc va, goc va

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 ky nang mai hoi. hieu va cham ((soc va) OR (hoc va)) dan ((dau cua) or (dai cua)) te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky nang mai hoi. hieu va cham ((soc va) OR (hoc va)) dan ((dau cua) OR (dai cua)) te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky nang mai hoi. hieu va cham ((soc va) OR (hoc va)) dan ((dau cua) or (dai cua)) te".
• Adding a wildcard symbol may retrieve word variants: te sach ky nang mai hoi. hieu va cham ((soc va) OR (hoc va)) dan ((dau cua) or (dai cua)) te*.