Perhaps you should try some spelling variations:
thanh mau » hanh mau, thanh san, thanh hai
thanh may » thanh tay, hanh may, thanh lay
dang mat » dang vat, dang mau, dung mat
tu sach » thu sach, su sach, te sach
cac toc » cac toi, cac nuoc, cac thoi
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
mat hoa » ma hoa, mai hoa, chat hoa
ky dang » ky nang, ky danh
duc tre » duoc tren, duc tien
toc va » hoc va, toc ta, tuc va
ve cac » va cac, vien cac

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 dang mat hoa. hieu ve cac toc va ((thanh may) or (thanh mau)) duc tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky dang mat hoa. hieu ve cac toc va ((thanh may) OR (thanh mau)) duc tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ky dang mat hoa. hieu ve cac toc va ((thanh may) or (thanh mau)) duc tre*.