Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
doan van » doan va, hoang van, luan van
chat luc » chat xuc, chat lua, nhan luc
hieu ve » hieu va, hieu van
van cua » vang cua, ban cua, dan cua
va doan » va doanh, van doan, va dan
ve chat » va chat, van chat
tu sach » su sach, te sach, tu cach
tang ma » mang may, tang van
nang ma » sang ma, nang cao, mang may
cua tre » cua te, cuu tre, cua triet
luc va » duc va, tuc va, loc va

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ky ((nang ma) OR (tang ma)) hoa. hieu ve chat luc va doan van cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (thu sach)) ky ((nang ma) OR (tang ma)) hoa. hieu ve chat luc va doan van cua tre~".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) ky ((nang ma) OR (tang ma)) hoa. hieu ve chat luc va doan van cua tre*.