The most reliable source for Islamic PDFs is the Internet Archive. Search for: "Sheikh Muhammad Jibreel Dua Arabic Archive.org" Look for user-uploaded compilations titled "Majmu' Ad'iyat al-Qari Muhammad Jibreel" (Collection of Reciter Muhammad Jibreel's Supplications). These are often scans of hand-typed Arabic scripts.
For mobile users, there are also like the Sheikh Muhammad Jibreel Dua APK that allow you to listen to these recordings offline. Shaykh Muhammad Jibreel | YasSarNalQuR'aN sheikh muhammad jibreel dua pdf arabic