Perhaps you should try some spelling variations:
dong hoa » dong hoc, dong co
so sach » so sanh, bo sach, co sach
su cham » su pham, tu cham, vu cham
luc van » luoc van, luu van, duc van
xuc van » duc van, vuc van, xuc ban
hieu su » hieu sau, tieu su, hieu so
sach ty » sach y, sach tu, sach thu
nang xa » nang x, lang xa, nang ma
cuu tre » cua tre, cau tren, cau treo
vi cuu » vi luu, vinh cuu

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ty ((nang xa) or (dong hoa)) hoi. hieu su cham ((xuc van) or (luc van)) hanh vi cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ty ((nang xa) OR (dong hoa)) hoi. hieu su cham ((xuc van) OR (luc van)) hanh vi cuu tre.
• Adding a wildcard symbol may retrieve word variants: so sach ty ((nang xa) or (dong hoa)) hoi. hieu su cham ((xuc van) or (luc van)) hanh vi cuu tre*.