Since this is not my area of expertise, I searched Google under the key words "spiral and elliptical galaxies" to get these possible sources:
https://www.google.com/search?client=safari&rls=en&q=spiral+and+elliptical+galaxies&ie=UTF-8&oe=UTF-8
In the future, you can find the information you desire more quickly, if you use appropriate key words to do your own search. Also see http://hanlib.sou.edu/searchtools/.
http://www.hackcollege.com/blog/2011/11/23/infographic-get-more-out-of-google.html
Don't just copy the material. Express the ideas in your own words. Although this will take more time and effort, you will learn more.
compare and contrast spiral and elliptical galaxies. (make at least 2 comparisons.)
2 answers
There is no common, but thanks anyway for the help dude those helped.