Thank you @brisby for your nice comment, I can understand what you mean about drawing noses, my weak point is drawing lips, somehow it takes me ages to get right angle and upper and lower lips, of course the highlights. But when you have done it right then this is really look realistic and impressive.

Thank you for your wonderful reflection to my article, I made a discovery for myself too, when I learnt that man who made a great input into economy in early ages and I am very pleased that you found the references useful :)