Perhaps you should try some spelling variations:
te sach » toc sach
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
hieu su » hieu sau, hieu so, hieu suat
tieu su » thieu so
dau cua » day cua, cau cua, dan cua
ma hoi » mai hoi, xa hoi, ma hoa
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 ma hoi. ((hieu su) OR (tieu su)) 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 ma hoi. ((hieu su) OR (tieu su)) 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 ma hoi. ((hieu su) OR (tieu su)) cham soc va dan ((dau cua) or (dai cua)) te".
• Adding a wildcard symbol may retrieve word variants: te sach ky nang ma hoi. ((hieu su) OR (tieu su)) cham soc va dan ((dau cua) or (dai cua)) te*.