[Solved] quote source from internet in my app?

Is it allowed, to quote from internet in my app? I provide the link, no question. But f.i. take a picture or drawing from a website, is this allowed, if I attach the link to this source?

I think not all website have same intellectual property policy. Some allow to use with credit or link back mentioned, some totally not allowed. Some allowed for education purpose but not commercial. Some required you to write to the owner to request for permission. Some website mentioned they use Creative Commons (CC) license which is safe to use.