Perhaps you should try some spelling variations:
hieu van » thien van, lieu va
sang tai » hang tai, sang tao, tang tai
tai khoa » da khoa, noi khoa
sach ky » sac ky, sach y, sach ty
cam tuc » cam xuc, cam tu, nam thuc
hieu va » lieu va, hieu qua
tu sach » thu sach, su sach, te sach
ky sang » ky nang, ky dang, ky tang
cuu tre » cua tre, cau tren, cau treo
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 tai khoa. ((((hieu ve) OR (hieu van))) 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 tai khoa. ((((hieu ve) OR (hieu van))) 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 tai khoa. ((((hieu ve) OR (hieu van))) or (hieu va)) cam tuc va dan va cuu tre*".