Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hanh vai » hanh vi, hanh tai, hanh van
hieu van » hieu va, thien van, lieu va
sach ky » sac ky, sach y, sach ty
hanh va » hang va, hanh vi
thuc va » thuc vat, thuc dan, thuc day
cua tre » cua te, cuu tre, cua triet
van cam » van nam, van lam, van cau
dang ma » dang mau, dang mam, dang mat
ky dang » ky nang, ky danh
tuc va » truc va, tuc xa, 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: toc sach ky dang ma hoa. hieu van cam ((tuc va) or (thuc va)) ((hanh vai) or (hanh va)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky dang ma hoa. hieu van cam ((tuc va) OR (thuc va)) ((hanh vai) OR (hanh va)) cua tre.
• Adding a wildcard symbol may retrieve word variants: toc sach ky dang ma hoa. hieu van cam ((tuc va) or (thuc va)) ((hanh vai) or (hanh va)) cua tre*.