To improve labor productivity, we must ensure the material basis of large-scale industry, that is, develop the production of fuel, iron, machinery manufacturing and chemical industry. Lenin
You think I just sat still and wrote five Gaby lines and five Gaby lines, and suddenly I succeeded! That's not what happened! I've been thinking about this problem for about 20 years. 19th century Russian chemist and discoverer of periodic law of elements Mendeleev.