Perhaps you should try some spelling variations:
hieu van » thien van, lieu va
cam truc » cau truc, nam truc, lam truoc
sang mai » sang ma, sang tai, lang mai
mai khoi » mai khoa, tai khoa, cac khoi
hanh vai » hanh vi, hanh va, hanh tai
vai cuu » vai cua
va hanh » van hanh, va thanh, va danh
truc va » thuc va, thuc vat, trung va
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
sach ky » sac ky, sach y, sach ty
ky sang » ky nang, ky dang, ky tang
cuu tre » cua tre, cau tren, cau treo

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 mai khoi. ((((hieu ve) OR (hieu van))) or (hieu va)) cam truc va hanh vai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky sang mai khoi. ((((hieu ve) OR (hieu van))) OR (hieu va)) cam truc va hanh vai cuu tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky sang mai khoi. ((((hieu ve) OR (hieu van))) or (hieu va)) cam truc va hanh vai cuu tre*".