Perhaps you should try some spelling variations:
thanh dai » thanh hai, thanh tai, thanh dat
toc sach » hoc sach, thuoc sach, nuoc sach
doc sach » hoc sach, nuoc sach, dac sac
ky dang » ky nang, ky danh
dang ma » dang mau, dang mam, dang mat
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, xa hoi, ma hoa
ve cam » ve cham, ve cac, va cam
xuc va » tuc va, luc va, xac va

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((toc sach) OR (doc sach)) ky dang ma hoi. hieu ve cam ((xuc va) or (duc va)) thanh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (doc sach)) ky dang ma hoi. hieu ve cam ((xuc va) OR (duc va)) thanh dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) OR (doc sach)) ky dang ma hoi. hieu ve cam ((xuc va) or (duc va)) thanh dai cua tre".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) OR (doc sach)) ky dang ma hoi. hieu ve cam ((xuc va) or (duc va)) thanh dai cua tre*.