Now is the time to be more specific with your searching. Articles tend to cover very specific or niche topics, and are also published more quickly than books, meaning the information is typically more current than the general information you can gather from books.
Possible keywords to use for this example: Mayan pottery Ceramics "Hero twins" Mayan Pre-Columbian Mesoamerican sculpture art carving relief serpent snake feathered serpent iconography symbolism religion Calakmul
Google Scholar is a great resource for articles. It searches across many disciplines and sources. Link your Google Scholar to your library account to get access to articles that might be behind a paywall. Here's how: