Step 1:
You can use any kind of a4-size paper you like for folding the book shaped box.
The other side is completely white.
Valley-fold over these three lines.

Step 8:
Push the corner to the left by making a valley-fold over the line on the left and a mountain-fold over the line on the right.
Do the same with the corner indicated by the pink arrow.

Step 6:
Press the layers between the two large arrows against each other, then fold them together over the short yellow line.
Do the same on the other corner, see small arrows.

Step 12:
Mountain-fold over the line on the right first, then over the line on the left.
Now the lid gets the same width as the box, see pink arrow.

Step 11:
Mountain-fold over the yellow line.
Fold a little to the right of the edge of the box, see pink arrow.

Step 10:
Valley-fold over this line.

Step 9:
Valley-fold over the short yellow line on the right and mountain-fold over the one on the left. Do the same on the edge below.
Valley-fold over the pink line while you do this.

Step 5:
Make an inside reverse fold on these two corners.

Step 7:
Make sharper folding lines, if necessary.
Do the same on the other two edges, see pink arrows.

Step 3:
Mountain-fold over these three lines, then turn the model.

Step 2:
Valley-fold over this line.

Step 4:
Fold the three white edges straight upwards.
First the edge on the right, then the two on the left.

This is a video by Joost Langeveld which also has instructions for the book shaped box, Joost is a popular artist from the Netherlands: