Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
hanh dao » lanh dao, thanh dat, thanh dam
dan hanh » dang hanh, dan khanh, dan thanh
thuc dan » thuc hanh, hoc dan, thuc vat
cam thuc » am thuc, nam thuc, cam thu
dao cua » dai cua, day cua, dan cua
van cam » van nam, van lam, van cau
cua tre » cua te, cuu tre, cua triet
lang xa » lang ha, dang xay, lang van
nang xa » nang x, nang ma, mang xa
sac ky » cac ky

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

• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sac ky) OR (sai ky)) ((nang xa) OR (lang xa)) hoi. hieu van cam thuc dan hanh dao cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sac ky) or (sai ky)) ((nang xa) OR (lang xa)) hoi. hieu van cam thuc dan hanh dao cua tre~".
• Adding a wildcard symbol may retrieve word variants: su ((sac ky) or (sai ky)) ((nang xa) OR (lang xa)) hoi. hieu van cam thuc dan hanh dao cua tre*.