Perhaps you should try some spelling variations:
thanh toan » thanh hoa, thanh san, tinh toan
nam thuc » nam thuoc, am thuc, nam thu
toan cuu » toan cau, toan cua, toan cao
va thanh » gia thanh, ban thanh, va tinh
tu sach » thu sach, su sach, te sach
cam tuc » cam xuc, cam tu, dam thuc
hieu ve » hieu va, hieu van
ky dang » ky danh
cuu tre » cua tre, cau tren, cau treo

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) OR (ky nang)) cau hoi. hieu ve ((cam tuc) or (nam thuc)) va thanh toan cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ky dang) OR (ky nang)) cau hoi. hieu ve ((cam tuc) OR (nam thuc)) va thanh toan cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ky dang) OR (ky nang)) cau hoi. hieu ve ((cam tuc) or (nam thuc)) va thanh toan cuu tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ky dang) OR (ky nang)) cau hoi. hieu ve ((cam tuc) or (nam thuc)) va thanh toan cuu tre*.