Proton Stripping Strengths for Levels ofC11

States of ${}_{}{}^{11}{}_{}{}^{}\mathrm{C}$ were studied with the ${}_{}{}^{10}{}_{}{}^{}\mathrm{B}({}_{}{}^3{}_{}{}^{}\mathrm{He},d){}_{}{}^{11}{}_{}{}^{}\mathrm{C}$ reaction at a bombarding energy of 21 MeV. The data were found to favor the assignments $J^{\pi }={\frac{7}{2}}^{+} \mathrm{and} {\frac{5}{2}}^{+}$ to the levels at 8.65 and 8.69 MeV, respectively. A distorted-wave analysis of the angular distributions for negative-parity states in ${}_{}{}^{11}{}_{}{}^{}\mathrm{C}$ yielded spectroscopic factors whose relative values agreed well with the predictions of Cohen and Kurath, even though the excited-state energies were found to be in better agreement with the predictions of the unified rotational model.