Install a memory stick with unetbootin iso (ubuntu to be installed last) li>
the memory stick and create a folder with the name of the distro installed li>
Drag the stylus all the files in the folder created li>
Now install the second distro in the memory stick repeat steps 4 through 7 li>
Now go to System> Administration> Startup Disk Creator li>
Select the iso of ubuntu and set if you want the persistence li>
Open the folder of the first distro created and open the file syslinux.cfg li>
Copy
the last few lines about the kernel (label etc) li>
Now open the file (in subfolder syslinux) txt.cfg and paste this the copied rows at the bottom li>
Open the folder of the second distro created and open the file syslinux.cfg
you do steps 12 and 13 li>
If by chance you have puppy after ‘label puppy’> ‘kernel vnlinux’ is transformed into ‘kernel / vnlinux’
and also intrd = / initr.gz (in short, the super string kernel) li>
Now copy the file to the distro in 1 and 2 / the stylus if it asks you to join but do not overwrite any file li>
Now you can boot from usb (first setting the bios pc) li>
will open the menu boot ubuntu but you will notice that at the bottom of the list there will be other distros li>