Perhaps you should try some spelling variations:
thanh tai » thanh hai, thanh toan, doanh tai
sang mai » sang ma, sang tai, lang mai
hanh tai » hang tai, han tai, hinh tai
tu sach » thu sach, su sach, te sach
truc va » thuc va, thuc vat, trung va
cua tre » cua te, cuu tre, cua triet
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
mai hoi » mai khoi, dai hoi, lai hoi
ky sang » ky nang, ky dang, ky tang
ve cam » ve cham, ve cac, va cam

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