Perhaps you should try some spelling variations:
vanh dai » van dai, vanh tai, lanh dao
tu sach » thu sach, su sach, te sach
thuc va » thuc vat, thuc dan, thuc day
va cham » va chat, va tham
ve cham » ve chat, vu cham, ve chim
nang ma » tang ma, sang ma, nang cao
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
tuc va » truc va, tuc xa, duc va
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: tu sach y nang ma hoi. hieu ((ve cham) OR (va cham)) ((tuc va) or (thuc va)) vanh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang ma hoi. hieu ((ve cham) OR (va cham)) ((tuc va) OR (thuc va)) vanh dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang ma hoi. hieu ((ve cham) OR (va cham)) ((tuc va) or (thuc va)) vanh dai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach y nang ma hoi. hieu ((ve cham) OR (va cham)) ((tuc va) or (thuc va)) vanh dai cua tre*.