How to get sources for alpine .iso image

Where can I find the sources for the iso image: http://dl-3.alpinelinux.org/alpine/v3.6/releases/x86_64/alpine-standard-3.6.2-x86_64.iso
I found the medata here "https://git.alpinelinux.org/cgit/aports/refs/?h=3.6-stable" which was used to build the iso image.
Like metadat, is there any place where i can find the corresponding sources

Thanks in advance for your help