NITSYN A. RELATIONSHIP OF THE SYMMETRY GROUP OF THE ORNAMENT ON THE SKETCH OF M. C. ESHER’S SKETCH ‘SEAHORSES’ WITH THE MOTIONS OF THE PLANE DESCRIBING THE CONSTRUCTION OF ITS FIGURED TILE. ППММ [Internet]. 2021Aug.15 [cited 2024May19];4(1):170-7. Available from: //ojs.kntu.net.ua/index.php/aqmm/article/view/114