Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
thanh toan » thanh hoa, thanh san, tinh toan
sach ky » sac ky, sach y, sach ty
ky mang » ky nang, ke mang, ky dang
may hoi » may thoi, tay hoi, mai hoi
hieu ve » hieu va, hieu van
luu van » cuu van, luan van, luu hanh
toan va » doan va, tran van, toan ban
ve cam » ve cham, ve cac, va cam
luc va » duc va, tuc va, loc va
thiet » thieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuoc sach ky mang may hoi. hieu ve cam ((luc va) or (luu van)) thanh toan va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach ky mang may hoi. hieu ve cam ((luc va) OR (luu van)) thanh toan va thiet.
• Adding a wildcard symbol may retrieve word variants: thuoc sach ky mang may hoi. hieu ve cam ((luc va) or (luu van)) thanh toan va thiet*.