Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu su » hieu sau, tieu su, hieu suat
cham so » cham soc, cham o, ham so
hieu so » thieu so
cuu tre » cua tre, cau tren, cau treo
hieu vu » hieu va, hieu ve, dieu vu
nang xa » nang x, lang xa, nang ma
sach v » sach va, sach y, sach 2
v nang » va nang, vu nang, van nang
va dan » ca dan, va dao, va dau
dan di » danh di, dan da, dan de
di cuu » di cau, di cua, dinh cuu
so va » so van, so vat, su 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) or (hieu so)))) cham so va dan 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) OR (hieu so)))) cham so va dan di cuu tre.
• Adding a wildcard symbol may retrieve word variants: toc sach v nang xa hoi. ((hieu vu) or (((hieu su) or (hieu so)))) cham so va dan di cuu tre*.