Perhaps you should try some spelling variations:
hieu cua » hieu qua, dieu cua, bieu cua
vat danh » va danh, van danh, luat danh
nam thuc » nam thuoc, am thuc, nam thu
danh vi » hanh vi, dinh vi, danh di
nang co » nang cao, nang doc, nang noi
cua nam » cua tam, cua ngan, cua nhan
lang ra » lang ha, lang xa, lang va
sach ky » sac ky, sach ty, sach kem
vi cua » vai cua, di cua
cua tu » cua tuc, cua su, cua cu

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

• Performing a fuzzy search may retrieve terms with similar spellings: su ((sach ky) or (sach y)) ((nang co) or (lang ra)) hoi. hieu cua nam thuc vat danh vi cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sach y)) ((nang co) OR (lang ra)) hoi. hieu cua nam thuc vat danh vi cua tu.
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) or (sach y)) ((nang co) or (lang ra)) hoi. hieu cua nam thuc vat danh vi cua tu*.