Motions of 1308 stars with large proper motions ({mu}>300mas/yr) up to 17 mag were investigated using the results of observations conducted with Pulkovo Normal Astrograph and images taken from data bases of sky surveys (DSS, SDSS DR12, WISE). Basic idea of search of double stars with this material is a comparison between long-term proper motion (POSS2-POSS1, epoch difference is about 50yr) and short-term proper motion (2MASS, SDSS, WISE, Pulkovo, epoch difference is about 10yr). Star is classified as delta-mu-binary candidate in the case of statistically significant difference of short-term and long-term proper motions. This condition is realised for 121 stars of our target list. Additional evidence of duplicity was obtained with comparison of our proper motions with data of several parallax determination programs. Analysis of accurate SDSS photometric values of our stars allows us to conclude that four stars (J0656+3827, J0838+3940, J1229+5332, J2330+4639) are probably binary systems which consist of wite dwarf + M-dwarf.