Perhaps you should try some spelling variations:
doc sach » hoc sach, toc sach, nuoc sach
cap phoi » cap cho
hieu ve » hieu va, hieu van
truc va » thuc va, trung va
hanh di » hanh vi, hanh de, hang di
va cap » va cac, va dap, va cao
ve cac » va cac, vien cac
di cua » dai cua, doi cua, de cua
y va » ly va, my va, ky va

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

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