Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hanh di » hanh vi, hanh de, hang di
truc va » thuc va, trung va
hieu va » lieu va, hieu qua
nang xa » lang xa, nang ma, mang xa
sach v » sach va, sach y, sach 2
va cau » van cau, va cac, va dau
di cua » dai cua, doi cua, de cua
cua te » cua tu

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 v ((nang xa) OR (nang x)) hoi. hieu va cau ((truc va) or (thuc vat)) hanh di cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach v ((nang xa) OR (nang x)) hoi. hieu va cau ((truc va) OR (thuc vat)) hanh di cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach v ((nang xa) OR (nang x)) hoi. hieu va cau ((truc va) or (thuc vat)) hanh di cua te".
• Adding a wildcard symbol may retrieve word variants: toc sach v ((nang xa) OR (nang x)) hoi. hieu va cau ((truc va) or (thuc vat)) hanh di cua te*.