Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
cua triet » cua viet, su triet, va triet
qua pham » quan pham, quy pham, qua cham
pham duy » pham duc
van hanh » van thanh, ban hanh, van anh
hanh tai » thanh tai, hang tai, han tai
ty sang » ty xang, ty hang, duy sang
sang ma » tang ma, nang ma, sang tao
duy van » duy vat, dung van
tai cua » thai cua, tai cuc, tri cua
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: ((thu hoach) or (thuoc sach)) ty sang ma hoi. hieu qua pham duy van hanh tai cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu hoach) OR (thuoc sach)) ty sang ma hoi. hieu qua pham duy van hanh tai cua triet.
• Adding a wildcard symbol may retrieve word variants: ((thu hoach) or (thuoc sach)) ty sang ma hoi. hieu qua pham duy van hanh tai cua triet*.