Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, lieu va
hanh ve » hanh va, hanh kem
cua tre » cua te, cuu tre, cua triet
van cam » van nam, van lam, van cau
nang ma » tang ma, sang ma, nang cao
y nang » ky nang, ly nang, v nang
ma hoi » mai hoi, xa hoi, ma hoa
tuc va » thuc va, truc va, duc va

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach y nang ma hoi. hieu van cam ((tuc va) or (tuc xa)) ((hanh ve) OR (hanh vi)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach y nang ma hoi. hieu van cam ((tuc va) OR (tuc xa)) ((hanh ve) OR (hanh vi)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach y nang ma hoi. hieu van cam ((tuc va) or (tuc xa)) ((hanh ve) OR (hanh vi)) cua tre".
• Adding a wildcard symbol may retrieve word variants: thu sach y nang ma hoi. hieu van cam ((tuc va) or (tuc xa)) ((hanh ve) OR (hanh vi)) cua tre*.