I’ve tried nearly everything with no success and I don’t know why… I have a tablular with 9 columns and the only solution I found for fitting it into textwidth is using adjustbox, which I don’t like because it scale the fonts it seems. So the numbers on my table can’t barely be seen:

Can anyone help me a little bit? Thanks!

begin{table}
    centering
    begin{adjustbox}{max width=textwidth}
    begin{tabular}{|c|c|c|c|c|c|c|c|c|}
       multicolumn{1}{c}{} &  multicolumn{4}{c|}{Conjunto de datos original}  & multicolumn{4}{c}{Conjunto de datos reducido} \
        cline{2-9}
       multicolumn{1}{c|}{} & Filtro I & Filtro R & Filtro V & Filtros I,R,V & Filtro I & Filtro R & Filtro V & Filtros I,R,V \

        hline

       begin{tabular}[c]{@{}c@{}}$q=0.62$\ citep{2007ApJ...662..564B} end{tabular}  & $43.2_{-4.7}^{+4.2}$ & $41.9_{-3.4}^{+3.6}$ & $47.0_{-6.3}^{+6.3}$ & $41.7^{+3.8}_{-4.1}$ & $41.0_{-3.4}^{+3.5}$ & $45.3_{-4.8}^{+4.1}$ & $42.6_{-4.9}^{+5.8}$ & $45.5^{+4.9}_{-4.9}$ \
        hline

        begin{tabular}[c]{@{}c@{}}$q=0.68$\ citep{2017MNRAS.472.2937H} end{tabular} & $44.6_{-4.0}^{+4.8}$ & $43.1_{-3.6}^{+4.4}$ & $48.8_{-7.1}^{+7.5}$ & $43.0^{+4.5}_{-4.4}$ & $42.2_{-3.6}^{+4.4}$ & $46.5_{-5.5}^{+4.9}$ & $44.0_{-5.3}^{+5.3}$ & $46.8^{+5.6}_{-5.2}$ \

        hline
 
       Bootstrapping & $47.1_{-1.5}^{+1.5}$ & $45.6_{-1.3}^{+1.3}$ & $44.8_{-2.0}^{+2.4}$ & - & $44.0_{-1.3}^{+1.4}$ & $43.0_{-1.3}^{+1.4}$ & $40.3_{-2.7}^{+2.5}$ & - \

        hline
    end{tabular}
    end{adjustbox}
    caption{Resumen de los valores de $i$ destacados, obtenidos mediante diferentes métodos.}
    label{resultados finales}
end{table}

I tried several other methods and the only one I found to “work” is to set manually the column padding instead of using adjustbox by adding to each one: @{hspace{0.5em}}:

But then I have those unaligned vertical lines and I don’t know how to deal with it… It’s been like 4 hours since I started to solve this problem and nothing worked at all.