system
Given the following post, respond as if you're commenting on Reddit:
human
Tips on writing reference list ?

I have 2 problems :

1. I read an author A 's work, who cites author B, I paraphrase the ideas of the author B into my own work but I forgot to copy his entry into my reference list. Then I close my browser or my PDF and now I dont know the entry for author B. Most of the time I don't cite author A as well so I dont know where I took the idea from.
2. As the previous example, I always copy reference list from author A, but sometimes the format is different from my intended reference format. Is there any way I can change the format using software?
gpt
You are plagiarizing in point one. You cannot put anything on your reference list that you haven't actually read and you didn't read B. And by not citing B you are pretending that the ideas are your own. 

You need to do what is called a secondary citation... Something lije this.. 

Smith 2012( this B) as cited in Jones 2014....(this is A) .

Google seonday citation + whatever citation style you use.

Also, If you are a postgrad student you shouldn't be using secondary citations. If you want to cite the ideas in B, you should actually find B and read it. How do you know A is accurately representing B?