Perhaps you should try some spelling variations:
nang mai » nang ma, nang tai, lang mai
hanh vai » hanh vi, hanh va, hanh tai
mai khoi » mai khoa, tai khoa, cac khoi
hieu va » lieu va, hieu qua
vai cuu » vai cua
va hanh » van hanh, va thanh, va danh
cam tuc » cam xuc, cam tu, nam thuc
cuu tre » cua tre, cau tren, cau treo
sach ky » sac ky, sach y, sach kem
hieu ve » hieu van
sach ty » sach y, sach tu, sach thu
tuc va » thuc va, truc va, tuc xa

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