Perhaps you should try some spelling variations:
mai khoi » mai khoa, tai khoa, cac khoi
te sach » toc sach
sach ky » sac ky, sach y, sach ty
mai hoi » dai hoi, lai hoi, mai doi
hieu va » lieu va, hieu qua
va cham » va chat, va tham
dau cua » day cua, cau cua, dan cua
soc va » hoc va, loc va, doc va
va dan » ca dan, va dao, va dau

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) OR (mai khoi)). hieu va cham soc 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) OR (mai khoi)). hieu va cham soc 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) OR (mai khoi)). hieu va cham soc va dan ((dau cua) or (dai cua)) te".
• Adding a wildcard symbol may retrieve word variants: te sach ky nang ((mai hoi) OR (mai khoi)). hieu va cham soc va dan ((dau cua) or (dai cua)) te*.