Blog2Social - Schedule post to social media like Facebook, Auto-post to Facebook, share blog posts to Facebook, Twitter, LinkedIn, Instagram - What are Twitter Cards?
Twitter Cards for Blogger
Twitter Card Validator - TweetPik
Twitter Cards: Boost your Visibility on Twitter
How to Set up a Twitter Card in WordPress (2 Simple Steps)
Twitter Card Validator
How to set up Twitter cards - Quora
What is a Twitter Card Validator and How to Use It?
Installing Twitter Cards on Your WordPress site
Twitter Card: Update Twitter Cards using the Validator Tool - hiroko.io
Twitter Cards Implementation With Websites
Twitter Card Generator | Validate tweets by Meta tags and Cards