Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
cau thuc » cau truc, cuu thuc, can thuc
nang xa » nang x, lang xa, nang ma
van cau » van dau, van hau, van chat
thuc va » thuc vat, thuc dan, thuc day
va danh » va dinh, va dan, va hanh
sac ky » cac ky, sai ky
di cua » doi cua, de cua, do cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu ((sac ky) or (sach y)) nang xa hoi. hieu van cau thuc va danh ((di cua) or (dai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((sac ky) OR (sach y)) nang xa hoi. hieu van cau thuc va danh ((di cua) OR (dai cua)) tre.
• Adding a wildcard symbol may retrieve word variants: thu ((sac ky) or (sach y)) nang xa hoi. hieu van cau thuc va danh ((di cua) or (dai cua)) tre*.