Perhaps you should try some spelling variations:
hanh tai » thanh tai, hang tai, han tai
van hanh » van thanh, ban hanh, van anh
sach ty » sach y, sach thu, xach tay
tuc van » thuc van, truc van, tuc va
cam tuc » cam xuc, cam tu, nam thuc
hieu va » lieu va, hieu qua
buu tre » cuu tre
nang ma » tang ma, sang ma, nang cao
sach tu » sach thu, cach tu, sach uu
va cam » va cham, va cac, va cao

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 ty) OR (sach tu)) ((nang ma) or (nang x)) hoi. hieu va cam tuc van hanh tai buu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ty) OR (sach tu)) ((nang ma) OR (nang x)) hoi. hieu va cam tuc van hanh tai buu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ty) OR (sach tu)) ((nang ma) or (nang x)) hoi. hieu va cam tuc van hanh tai buu tre".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ty) OR (sach tu)) ((nang ma) or (nang x)) hoi. hieu va cam tuc van hanh tai buu tre*.