Perhaps you should try some spelling variations:
va danh » va dinh, va dan, va hanh
cac loc » cac lop, cac toc, cac hoc
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, mang xa
nang ma » tang ma, sang ma, nang cao
can ky » van ky, dan ky, ban ky
loc va » hoc va, luc va
vi cua » vai cua, di cua
de cua » le cua, te cua, dieu cua
tu can » tu ban, tu cac, thu canh

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu can ky ((nang xa) or (nang ma)) hoi. hieu va cac loc va danh ((vi cua) or (de cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu can ky ((nang xa) OR (nang ma)) hoi. hieu va cac loc va danh ((vi cua) OR (de cua)) tre.
• Adding a wildcard symbol may retrieve word variants: tu can ky ((nang xa) or (nang ma)) hoi. hieu va cac loc va danh ((vi cua) or (de cua)) tre*.