Perhaps you should try some spelling variations:
cau thuc » cau truc, cuu thuc, can thuc
cua viet » hoa viet, cua vat, cua dieu
thanh ha » thanh hoa, thanh hai, nhanh ha
hieu van » hieu va, thien van, lieu va
va thanh » gia thanh, ban thanh, va tinh
vu sach » vu bach, su sach, vu khach
cua tre » cua te, cuu tre, cua triet
thuc va » thuc vat, thuc dan, thuc day
sach ty » sach y, sach tu, sach thu
van cau » van dau, van hau, van chat
tang ma » mang may, tang van
ty tang » tay tang, ty xang, ty hang
ca viet » va viet, co viet, hoa viet
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: vu sach ty tang ma hoi. hieu van cau thuc va thanh ha ((cua tre) or (((cua viet) OR (ca viet))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ty tang ma hoi. hieu van cau thuc va thanh ha ((cua tre) OR (((cua viet) OR (ca viet)))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ty tang ma hoi. hieu van cau thuc va thanh ha ((cua tre) or (((cua viet) OR (ca viet))))".
• Adding a wildcard symbol may retrieve word variants: vu sach ty tang ma hoi. hieu van cau thuc va thanh ha ((cua tre) or (((cua viet) OR (ca viet))))*.