Pinterest is fine for general studies but finding the right reference, especially those geared at the anime-type art, it can be frustrating
Here are some of great reference resources I've come across:

Pose Search
Good for when need a specific anatomy ref from a specific angle
It focuses on one joint at a time
- Adjust a 3D skeleton to match the pose and camera angle you need (requires a mouse)
- Once you're happy with the pose, hit the Search button
- Then it'll pull up photos with similar poses and angles
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360°图片征集
- GIF collection featuring various figures photographed in full 360° rotations
- Great for studying how 2D character designs translate into 3D forms
- Same for studying female anime characters proportions
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lovechara
- 360° clothing reference photos in various poses and angles
- Very useful for kimono references
- Also has a Twitter account with some posted as rotating GIFs
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ATTORIAL
- Requires a free account to view images
- Click the Croquis (크로키) tab to access the pose library
- Includes a wide variety of poses and camera angles commonly used in anime illustrations
- Save ref photos to your account using the ⭐ icon
- Also includes a built-in timer for croquis practice
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Others:

- Digital download
- Designed for stylish illustrations and comics
- Tracing is permitted
- Includes:
- 46 sword poses
- 57 special poses
- Around 100 reference photos in total
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- Link is for the Kindle (digital) edition
- Designed for stylish illustrations and comics
- Tracing is permitted
- Covers a wide range of poses, including:
- Sword fighting
- Gunplay
- Floating and mid-air poses
- And more