00310nam a2200121Ia 4500008004100000020001800041041000800059082001700067100002100084245005600105260001900161300000800180211209s2019 xx 000 0 und d a9783030042530 aeng a658.4035 PET aPETROV, VLADIMIR aTRIZ. THEORY OF INVENTIVE PROBLEM SOLVING: LEVEL 1  bSPRINGERc2019 a221