Perhaps you should try some spelling variations:
thanh bac » nhanh bac, thanh bai, thanh san
hanh bac » nhanh bac, hanh cac, danh bac
hanh tri » thanh tri, hanh tai, hanh trinh
van hanh » van thanh, ban hanh, van anh
xuc van » duc van, luc van, vuc van
so sach » so sanh, bo sach, co sach
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
cua tre » cua te, cuu tre, cua triet

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ky ((nang xa) OR (nang ma)) hoi. thi ((hanh bac) or (thanh bac)) xuc van hanh tri cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky ((nang xa) OR (nang ma)) hoi. thi ((hanh bac) OR (thanh bac)) xuc van hanh tri cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ky ((nang xa) OR (nang ma)) hoi. thi ((hanh bac) or (thanh bac)) xuc van hanh tri cua tre".
• Adding a wildcard symbol may retrieve word variants: so sach ky ((nang xa) OR (nang ma)) hoi. thi ((hanh bac) or (thanh bac)) xuc van hanh tri cua tre*.