Perhaps you should try some spelling variations:
doc sach » hoc sach, toc sach, nuoc sach
cac phoi » cac thoi, cac khoi, cap phoi
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
truc va » thuc va, trung va
hanh di » hanh vi, hanh de, hang di
ve cam » ve cham, ve cac, va cam
di cua » dai cua, doi cua, de cua
ky va » ly va, ke va, my va

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc sach ky va cac phoi. hieu ve cam ((truc va) or (thuc vat)) hanh di cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc sach ky va cac phoi. hieu ve cam ((truc va) OR (thuc vat)) hanh di cua vat.
• Adding a wildcard symbol may retrieve word variants: doc sach ky va cac phoi. hieu ve cam ((truc va) or (thuc vat)) hanh di cua vat*.