Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
nang may » mang may, nang ma, bang may
may khoa » da khoa, ly khoa, y khoa
hieu va » lieu va, hieu qua
vai cau » va cau, van cau, vai cac
dan vai » dan va, dan tai, dan vat
cam luc » cam xuc, cau luc
su sach » so sach
hieu ve » hieu van
vu sach » vu bach, vu khach
luc va » duc va, tuc va, loc 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: ((su sach) OR (vu sach)) ky nang may khoa. ((hieu ve) or (hieu va)) cam luc va dan vai cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (vu sach)) ky nang may khoa. ((hieu ve) OR (hieu va)) cam luc va dan vai cau tren*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) OR (vu sach)) ky nang may khoa. ((hieu ve) or (hieu va)) cam luc va dan vai cau tren*".