Perhaps you should try some spelling variations:
quoc quan » qua quan, luc quan, hoc quan
hieu van » hieu va, thien van, lieu va
sach ty » sach y, sach tu, sach thu
nang xa » nang x, lang xa, nang ma
van cam » van nam, van lam, van cau
xuc san » xuc ban, luc sang, nuoc san
benh va » benh ve, benh dai, benh tai
cuu tre » cua tre, cau tren, cau treo
sac ky » cac ky, sai ky
va cuu » va cau, va chu, va huu

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((sach ty) or (sac ky)) nang xa hoi. hieu van cam ((xuc san) or (quoc quan)) benh va cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ty) OR (sac ky)) nang xa hoi. hieu van cam ((xuc san) OR (quoc quan)) benh va cuu tre.
• Adding a wildcard symbol may retrieve word variants: tu ((sach ty) or (sac ky)) nang xa hoi. hieu van cam ((xuc san) or (quoc quan)) benh va cuu tre*.