With proper references and credits.
Edit: I am using couple of pictures, one as an e-book cover and the rest for decorating the head of various chapters. The pictures are insignificant for the scientific e-book.
With proper references and credits.
Edit: I am using couple of pictures, one as an e-book cover and the rest for decorating the head of various chapters. The pictures are insignificant for the scientific e-book.
No, you cannot put additional restrictions on the picture, and re-licensing it with a 'non-commercial' restriction would be incompatible with the 'share alike' in the CC BY SA 4.0 terms. The definition of 'Adapted Material' in the license language of CC BY SA 4.0 is very broad. Your book would be 'Adapted Material' according to the license terms and therefore would need to be following the 'share alike' requirement, so with the same license or any of the compatible licenses. Please see also the FAQ.