https://engineering.futureuniversity.com/BOOKS FOR IT/Professional_Android_Application_Development.pdf,
https://web.stanford.edu/class/cs231m/lectures/lecture-2-android-dev.pdf,
https://developer.android.com/developer-verification/guides/pdf-guides/adc-guide.pdf,
https://pubs.aip.org/aip/acp/article-pdf/doi/10.1063/5.0116494/16648807/020087_1_online.pdf,
https://moodle.skillscommons.org/mod/resource/view.php?id=140,
https://www.mdc.edu/asa/documents/competencies/pdf/COP2660 Android Application Development 1.pdf,
http://repo.darmajaya.ac.id/4534/1/Android Studio 2.3 Development Essentials - Android 7 Edition ( PDFDrive ).pdf,
https://ieeexplore.ieee.org/iel7/9018087/9032424/09032440.pdf,
https://shop.digicelgroup.com/zbalancex/istampr/jl252605/L9424163J2175535/android_application_development__programming_with-the-google-sdk.pdf,
https://adeption.io/wp-content/uploads/2020/02/Adeption-Android-Developer.pdf,
https://moodle.mtu.edu.ng/mtiev/ascrews/8Y1151Z/180118210426/head_first-android__development_2e.pdf,
http://coolt.ch/notizen/wp-content/uploads/2016/02/Head-First-Android-Development-2015.pdf,
https://www.developer-bootcamp.com/pdf/android-programming-course.pdf,
http://blog.centurylink.com/echoken/dreachc/070631/73437AC/android-development_patterns__best_practices__for_professional_developers-developer-s__library.pdf,
https://www.dre.vanderbilt.edu/~schmidt/cs282/PDFs/DevelopmentEnvironment.pdf,
https://moleculight.com/wp-content/uploads/2018/07/Job-Description-for-Android-Developer-Jun-2018-Rev1.1.pdf,
https://roadmap.sh/pdfs/roadmaps/android.pdf,
https://www.iosrjournals.org/iosr-jce/papers/conf.15013/Volume 3/6. 28-32.pdf,
https://www.kufunda.net/publicdocs/The Android Programming Guide A Comprehensive Guide for Seniors and Beginners to Understand Android Programming ( etc.).pdf,
https://androidatc.com/upload/editor_upload/file/Java-Fundamentals-for-AndroidT-Application-Development-AND-404.pdf,
https://gogotraining.com/media/downloads/outlines/Introduction-Android-Programming-training-course-499.pdf,
https://www.govinfo.gov/content/pkg/GOVPUB-D101-PURL-gpo125176/pdf/GOVPUB-D101-PURL-gpo125176.pdf,
https://www.rcet.org.in/uploads/academics/regulation2021/rohini_36302937143.pdf,
https://hris.mohs.gov.sl/default.aspx/mL8G7C/604389/Android App Development For Dummies.pdf,
https://cvhcp.com/wp-content/uploads/formidable/8/Hire-ExpertAndroidDeveloperforCustomMobileSolutions.pdf,
https://ihris.health.gov.mw/default.aspx/mL6C79/603299/Android Application Development Self Study Guide.pdf,
https://www.doi.gov/sites/doi.gov/files/uploads/Android.pdf,
https://www.etenders.gov.za/home/Download/?blobName=cfc55acc-db13-4d87-81f8-2ab9444f7c11.pdf&downloadedFileName=Android Developer job spec.pdf,
https://bonigarcia.dev/learning/mobile-applications/MA_01-android_intro_v1.pdf,
https://www.longdom.org/open-access-pdfs/exponential-growth-of-mobile-technology-and-their-impact-on-android-development-in-future.pdf,
https://www.scitepress.org/Papers/2020/97703/97703.pdf,
https://google-developer-training.github.io/android-developer-advanced-course-practicals/android-developer-advanced-course-practicals.pdf,
https://cs.wmich.edu/gupta/teaching/cs6030/6030cloudSummII2020web/lectureNotes6030cloud/Android Developer Roadmap - Learn to become an Android developer.pdf,
https://iris.polito.it/retrieve/handle/11583/2837799/e384c432-587e-d4b2-e053-9f05fe0a1d67/KotlinPaperR3.pdf,
https://www.aau.at/wp-content/uploads/2019/11/Beyer2014-posts.pdf,
http://repo.darmajaya.ac.id/5623/1/Android Studio 3.0 Development Essentials  - Android 8 Edition ( PDFDrive ).pdf,
https://ijrpr.com/uploads/V6ISSUE5/IJRPR45232.pdf,