Rudra Gita contains verses dedicated to Srihari Vishnu – it extols the glory of Vishnu. Rudra Gita is found in Srimad Bhagavad Purana (shlokas 16 – 79 of chapter 24 of 4th canto) and also in Varaha Purana (Chapters 70 to 72). This particular Rudra Gita is in English in pdf format.
The holy text mainly narrates the importance of Vishnu worship – a path to moksha. It also talks about core teachings in Hinduism.
Link – Rudra Gita in pdf