Name dropping
The amount of @names at some point starts to resemble ' namedropping ' and results in a messy timeline. That's why I often prefer not to start a message with 'RT @nameoftwitterer' but to end it with 'via @nameoftwitterer'. That way a tweet starts with the content and then the reference follows; in a busy timeline it's more pleasant to first take in the content and then see the reference.
Recommended
In addition, I feel that mentioning an @name in a retweet is a good idea, I am indicating that others can take a closer look at this source. If I retweet your @name in an article, I am exposing my Twitter followers to this information, I do not want to tire them with accounts that are not worth following. After all, I am only interested in the viral effect of the dissemination of information and not so much in your increasing number of followers. If an increase in Twitter followers is your motivation to share information, then I advise you to become more relevant
Make sure that you do not only display the content of a message but also add your opinion. Provide a link to an article of your vision or interpretation. This way more people are inclined to copy your messages with mention of your name. A practical obstacle is the length of a tweet, so always make sure that there is enough space for 'RT @pietervlamings' or 'via @pietervlamings'. By shortening the link itself with a URL shortener you also have the possibility to provide it with some branding. I sometimes use vlamin.gs myself to add this to a URL.
Macro-micro blogging
If you want to share information and you can't do without the recognition that it was you india phone number list who found the information: start a macro-micro-blog. A bit more extensive than on Twitter, you can provide the found information with a short explanation or introduction. Take information over to your own blog/ tumbler page. Provide a new tool or handy website with some explanation and your own name or brand will gain more attention, now that you have become part of the source and explanation.
What you share is not always unique
Information flows freely on the internet and sources often overlap. So don't assume that a shared link or message has you as the source and that you can be angry about missing the retweet with attribution. Even though I follow you, my timeline is quite busy and I'm not glued to Twitter 24/7. In fact, I'm quite busy with work and other things and who knows, fifteen minutes after you post it in my timeline, the same message from a different source may appear.
Opinion
Asking someone why the retweet lacks information is therefore rather strange in my opinion. This article is therefore entirely my opinion. I invite everyone to have a nice discussion about the etiquette of retweeting and mentioning the @source. My belief is not set in stone and I certainly make the above 'mistakes' myself. It remains social media and etiquette is set by all of us.