Perhaps you should try some spelling variations:
thanh dai » thanh hai, thanh tai, thanh oai
thanh dat » thanh san, thanh hai, thanh van
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
cua tre » cua te, cuu tre, cua triet
luc va » duc va, tuc va, loc va
va cam » va cham, va cao, va cai
ma hoi » mai hoi, xa hoi, ma hoa

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 nang ma hoi. hieu ((va cam) OR (va cac)) luc va ((thanh dai) or (thanh dat)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ma hoi. hieu ((va cam) OR (va cac)) luc va ((thanh dai) OR (thanh dat)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ma hoi. hieu ((va cam) OR (va cac)) luc va ((thanh dai) or (thanh dat)) cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ma hoi. hieu ((va cam) OR (va cac)) luc va ((thanh dai) or (thanh dat)) cua tre*.