Perhaps you should try some spelling variations:
mai khoi » mai khoa, tai khoa, cac khoi
nang mai » nang ma, nang tai, lang mai
hanh tai » thanh tai, hang tai, han tai
tu sach » thu sach, su sach, tu cach
te sach » toc sach
duc ban » duc tan, duc van, duc man
dua ban » dia ban, cua ban, qua ban
buu tre » cuu tre

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) or (te sach)) ky nang mai khoi. lieu va cac ((duc ban) OR (dua ban)) hanh tai buu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) ky nang mai khoi. lieu va cac ((duc ban) OR (dua ban)) hanh tai buu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (te sach)) ky nang mai khoi. lieu va cac ((duc ban) OR (dua ban)) hanh tai buu tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (te sach)) ky nang mai khoi. lieu va cac ((duc ban) OR (dua ban)) hanh tai buu tre*.