What Pencils Did You Use for the Sketches in Your Answer?

What pencils did you use for the sketches in your answer? Can you share links to the books about sketching?

Choosing a size for Sketchbook. a5 would be apt. It opens to a working are of a4, Where you can create small intricate sketches to detailed ones. T are convenient to use and easy to carry. If you like drawing on a big scale, a4 would be helpful. It opens up to a size of a3. For me, Time matters. It takes at least 1–2 hours for completing the sketch. a3 would take much more time and will need a bigger bag to carry it. Then there are smaller sketchbooks like a6. Those are extremely portable and you can even fit them into your pocket. T are light and great for carrying anywhere. Switching sizes is a good way to mix up your style and help you think different.