Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
va triet » va thiet, va trien, ve triet
trinh su » trinh tu, trinh san, trinh cau
cham tuc » nham thuc, pham thuc, cham soc
tinh su » hinh su, tinh tu, dinh su
tu sach » thu sach, su sach, te sach
sach tu » sach thu, cach tu, sach ty
hieu ve » hieu va, hieu van
tu nano » truc nano
nano x » nano 1, nano o
x hoi » xa hoi, o hoi, x ho

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 nano x hoi. hieu ve ((cham tuc) OR (tham thuc)) va ((tinh su) or (trinh su)) va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach tu nano x hoi. hieu ve ((cham tuc) OR (tham thuc)) va ((tinh su) OR (trinh su)) va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach tu nano x hoi. hieu ve ((cham tuc) OR (tham thuc)) va ((tinh su) or (trinh su)) va triet".
• Adding a wildcard symbol may retrieve word variants: tu sach tu nano x hoi. hieu ve ((cham tuc) OR (tham thuc)) va ((tinh su) or (trinh su)) va triet*.