Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hanh tinh » hanh trinh, nhanh tinh, thanh tinh
hanh sinh » hanh dinh, hinh sinh, hanh chinh
hieu van » hieu va, thien van, lieu va
cam thuc » am thuc, nam thuc, cam thu
tu sach » thu sach, su sach, te sach
sach tu » sach thu, cach tu, sach ty
van cam » van nam, van lam, van cau
tang o » trang o, lang o
xang o » lang o, dang o

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