Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
nang xa » nang x, lang xa, nang ma
hieu vu » hieu va, hieu ve, dieu vu
hieu su » hieu sau, tieu su, hieu so
cham su » cham soc, cham cuu, achat su
va hanh » van hanh, va thanh, va danh
hanh di » hanh vi, hanh de, hang di
cuu tre » cua tre, cau tren, cau treo
sach v » sach va, sach y, sach 2
v nang » va nang, vu nang, van nang
di cuu » di cau, di cua, dinh cuu
su va » su van, tu 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 v nang xa hoi. ((hieu vu) or (hieu su)) cham su va hanh di cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach v nang xa hoi. ((hieu vu) OR (hieu su)) cham su va hanh di cuu tre.
• Adding a wildcard symbol may retrieve word variants: toc sach v nang xa hoi. ((hieu vu) or (hieu su)) cham su va hanh di cuu tre*.