Perhaps you should try some spelling variations:
thanh toan » thanh hoa, thanh san, tinh toan
thanh tay » thanh tai, thanh thuy, thanh san
van hanh » van thanh, ban hanh, van ban
tu sach » thu sach, su sach, te sach
van anh » van thanh, tuan anh, van minh
ca tren » cau tren, cu tren, la tren
cam luc » cam xuc, cau luc
sach ky » sac ky, sach y, sach ty
va cam » va cham, va cac, va cao
ve ca » ve cac, ve cai, ve cau

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 ((thanh tay) or (thanh toan)) hoi. lieu va cam luc ((van hanh) OR (van anh)) ve ca tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((thanh tay) OR (thanh toan)) hoi. lieu va cam luc ((van hanh) OR (van anh)) ve ca tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((thanh tay) or (thanh toan)) hoi. lieu va cam luc ((van hanh) OR (van anh)) ve ca tren".
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((thanh tay) or (thanh toan)) hoi. lieu va cam luc ((van hanh) OR (van anh)) ve ca tren*.