Perhaps you should try some spelling variations:
tai khoa » da khoa, noi khoa
tu sach » thu sach, su sach, te sach
cam tuc » cam xuc, cam tu, nam thuc
hieu va » lieu va, hieu qua
cuu tre » cua tre, cau tren, cau treo
hieu ve » hieu van
ky tang » ky nang, ky dang, kho tang
ky sang » ky nang, ky dang, duy sang
tuc va » thuc va, truc va, tuc xa
va dan » ca dan, va dao, va dau
dan va » doan va, dan ca, ban va
va cuu » va cau, va chu, va huu

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ((ky sang) OR (ky tang)) tai khoa. ((hieu ve) or (hieu va)) cam tuc va dan va cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ky sang) OR (ky tang)) tai khoa. ((hieu ve) OR (hieu va)) cam tuc va dan va cuu tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ky sang) OR (ky tang)) tai khoa. ((hieu ve) or (hieu va)) cam tuc va dan va cuu tre*".