[en] The excitation function of the ${}^{nat}$Zr(p,x)${}^{90}$Nb, ${}^{nat}$Zr(p,x)${}^{91m}$Nb and ${}^{nat}$Zr(p,x)(p,x)${}^{92m}$Nb reactions were measured within the incident proton energies range of 10.58 MeV to 43.61 MeV, based on the stacked-foil activation technique. The degradation of proton energy along the sample stack was calculated using the code SRIM-2013, and the proton flux was determined by using the ${}^{nat}$Cu(p,x)${}^{62,65}$Zn monitor reactions. The induced $\mathrm{\gamma <!--\; ??\; -->}$-ray activity needed to determine the reaction cross-section was measured by using an HPGe detector. The measured cross sections are compared with the literature data and with the theoretical predictions based on TALYS-1.95 code. For the theoretical calculations, the effect of different level density models and $\mathrm{\gamma <!--\; ??\; -->}$-ray strength functions was taken into account. Besides the measured excitation functions, the integral yields of ${}^{90}$Nb, ${}^{91m}$Nb and ${}^{92m}$Nb formation were also calculated.