Perhaps you should try some spelling variations:
thanh toan » thanh hoa, thanh san, tinh toan
ban thanh » ban hanh, ban hang
toan cua » than cua, tan cua, doanh cua
cua tre » cua te, cuu tre, cua triet
cao duc » dao duc, cao suc, giao duc
su sach » so sach, vu sach
ky tang » ky nang, ky dang, kho tang
tang ma » mang may, tang van
hieu ve » hieu va, hieu van
cam duc » cam xuc, pham duc, nam duoc
su sac » su cac, su xac
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: ((su sac) or (su sach)) ky tang ma hoi. hieu ve ((cam duc) OR (cao duc)) ban thanh toan cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sac) OR (su sach)) ky tang ma hoi. hieu ve ((cam duc) OR (cao duc)) ban thanh toan cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sac) or (su sach)) ky tang ma hoi. hieu ve ((cam duc) OR (cao duc)) ban thanh toan cua tre".
• Adding a wildcard symbol may retrieve word variants: ((su sac) or (su sach)) ky tang ma hoi. hieu ve ((cam duc) OR (cao duc)) ban thanh toan cua tre*.