Perhaps you should try some spelling variations:
cham truc » cau truc, nham thuc, pham thuc
cua viet » ca viet, hoa viet, cua vat
hieu van » hieu va, thien van, lieu va
thanh va » thanh van, hanh va, thanh ha
thanh vi » hanh vi, thanh ve, nhanh vi
van cham » van chat, van tham, va cham
tang ma » mang may, tang van
truc va » thuc va, thuc vat, trung va
so sanh » do sanh
ma hoi » mai hoi, xa hoi, ma hoa
y tang » ky tang, 6 tang, 7 tang

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((so sanh) or (cho sinh)) y tang ma hoi. hieu van cham truc va ((thanh vi) OR (thanh va)) cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((so sanh) OR (cho sinh)) y tang ma hoi. hieu van cham truc va ((thanh vi) OR (thanh va)) cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((so sanh) or (cho sinh)) y tang ma hoi. hieu van cham truc va ((thanh vi) OR (thanh va)) cua viet".
• Adding a wildcard symbol may retrieve word variants: ((so sanh) or (cho sinh)) y tang ma hoi. hieu van cham truc va ((thanh vi) OR (thanh va)) cua viet*.