A beautiful collection of  4 explanations to the famous Aqidah of Imam Ahmad ibn Hanbali entitled Usul as-Sunnah:
- Shaykh Ahmad an-Najmi
- Shaykh Rabi' al-Madkhali
- Shaykh Zayd al-Madkhali
- Shaykh 'Ubayd al-Jabiri
Very nice edition with authentication of Hadiths and referencing of quotes.