Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hieu van » hieu va, thien van, lieu va
hanh doi » thanh doi, hanh noi, hang doi
cam thuc » am thuc, nam thuc, cam thu
sach doi » sach hoi, sach moi, sach dao
sach lo » sach dao, sach hoi, sach moi
van cam » van nam, van lam, van cau
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
doi cua » dai cua, hoi cua
va hoi » va hoc, va hoa

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 lo) OR (sach doi)) hang ((va hoi) or (xa hoi)). hieu van cam thuc va hanh doi cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach lo) OR (sach doi)) hang ((va hoi) OR (xa hoi)). hieu van cam thuc va hanh doi cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach lo) OR (sach doi)) hang ((va hoi) or (xa hoi)). hieu van cam thuc va hanh doi cua triet".
• Adding a wildcard symbol may retrieve word variants: tu ((sach lo) OR (sach doi)) hang ((va hoi) or (xa hoi)). hieu van cam thuc va hanh doi cua triet*.