shoes package:MASS R Documentation _S_h_o_e _w_e_a_r _d_a_t_a _o_f _B_o_x, _H_u_n_t_e_r _a_n_d _H_u_n_t_e_r _D_e_s_c_r_i_p_t_i_o_n: A list of two vectors, giving the wear of shoes of materials A and B for one foot each of ten boys. _U_s_a_g_e: shoes _S_o_u_r_c_e: G. E. P. Box, W. G. Hunter and J. S. Hunter (1978) _Statistics for Experimenters._ Wiley, p. 100 _R_e_f_e_r_e_n_c_e_s: Venables, W. N. and Ripley, B. D. (2002) _Modern Applied Statistics with S._ Fourth edition. Springer.