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+++ b/source.md
@@ -81,16 +81,21 @@ If you appreciate the content 📖, support projects visibility, give 👍| ⭐|
 - [Firebase Chat](https://codelabs.developers.google.com/codelabs/flutter-firebase/#0) - Firebase integration by Google Code Labs
 - [Planets-Flutter: from design to app](http://sergiandreplace.com/2017/09/planets-flutter-from-design-to-app) - Detailed planets design tutorial
 - [Todo List](https://github.com/lesnitsky/todolist_flutter) <!--stargazers:lesnitsky/todolist_flutter--> – Step by step tutorial how to build Todo List with Flutter by [Andrei Lesnitsky](https://twitter.com/lesnitsky_dev)
+- [Flutter and Dart development](https://suragch.medium.com/flutter-and-dart-development-articles-981be9ef7b23) - Articles and tutorials by [Suragch](https://twitter.com/Suragch1)
 
 ### Beginner
 
 - [Roadmap to Flutter Development](https://github.com/olexale/flutter_roadmap) <!--stargazers:olexale/flutter_roadmap--> - Visual roadmap with principles, patterns, and frameworks for Flutter newbies by [Olexandr Leuschenko](https://github.com/olexale).
 - [Layout Cheat Sheet](https://medium.com/flutter-community/flutter-layout-cheat-sheet-5363348d037e) - Extensive examples of layout widgets by [Tomek Polański](https://github.com/tomaszpolanski)
+- [Getting Started with Flutter](https://www.raywenderlich.com/24499516-getting-started-with-flutter) - by [raywenderlich.com](https://www.raywenderlich.com)
 
+### Intermediate
+
+- [Flutter state management for minimalists](https://suragch.medium.com/flutter-state-management-for-minimalists-4c71a2f2f0c1?sk=6f9cedfb550ca9cc7f88317e2e7055a0) - Understanding app architecture without relying on third-party frameworks by [Suragch](https://twitter.com/Suragch1). See also [State Management](#state-management)
 
 ### Advanced
 
-- [Rendering Pipeline](https://www.youtube.com/watch?v=UUfXWzp0-DU) <!--youtube:video/UUfXWzp0-DU--> - Engine architecture by Adam Barth
+- [Rendering Pipeline](https://www.youtube.com/watch?v=UUfXWzp0-DU) <!--youtube:video/UUfXWzp0-DU--> and [Let's build a render tree](https://www.youtube.com/watch?v=VsYbFnucHsU) - Engine architecture by Adam Barth
 - [Render Objects](https://medium.com/flutter-community/flutter-what-are-widgets-renderobjects-and-elements-630a57d05208) <!--claps:flutter-community/flutter-what-are-widgets-renderobjects-and-elements-630a57d05208--> - What are Widgets, RenderObjects and Elements? by [Norbert515](https://github.com/Norbert515)
 - [Streams and RxDart](https://skillsmatter.com/skillscasts/12254-flutter-with-streams-and-rxdart) - Skillmatters presentation by [Brian Egan](https://github.com/brianegan)
 - [Gesture System](https://medium.com/flutter-community/flutter-deep-dive-gestures-c16203b3434f) <!--claps:flutter-community/flutter-deep-dive-gestures-c16203b3434f--> - Flutter Deep Dive: Gestures by [Nash](https://github.com/nash0x7e2)
@@ -324,6 +329,7 @@ If you appreciate the content 📖, support projects visibility, give 👍| ⭐|
 - [Audio Recorder](https://github.com/ZaraclaJ/audio_recorder) <!--stargazers:ZaraclaJ/audio_recorder--> - Record audio and store it locally by [Jordan Alcaraz](https://twitter.com/jordanalcrz)
 - [Flutter Sound](https://github.com/dooboolab/flutter_sound) <!--stargazers:dooboolab/flutter_sound--> - Flutter audio recorder and player at one hand by [dooboolab](https://github.com/dooboolab)
 - [AssetsAudioPlayer](https://github.com/florent37/Flutter-AssetsAudioPlayer) <!--stargazers:florent37/Flutter-AssetsAudioPlayer-->  Simultaneous playback of audio from assets/network/file and displaying notifications [android / ios / web / macos]
+- [Audio Service](https://pub.dev/packages/audio_service) - System background audio support by [Ryan Heise](https://github.com/ryanheise). [Tutorial](https://suragch.medium.com/background-audio-in-flutter-with-audio-service-and-just-audio-3cce17b4a7d?sk=0837a1b1773e27a4f879ff3072e90305) by [Suragch](https://twitter.com/Suragch1).
 
 #### Video
 
@@ -608,6 +614,7 @@ This section contains libraries that take an experimental or unorthodox approach
 - [Flutter Files](https://marketplace.visualstudio.com/items?itemName=gornivv.vscode-flutter-files) - Quick generation for BLoC templates files by context menu by [Gorniv](https://github.com/gorniv).
 - [Flutter Intl](https://marketplace.visualstudio.com/items?itemName=localizely.flutter-intl) - i18n binding from arb files by [Localizely](https://twitter.com/localizely)
 
+
 ### IntelliJ / Android Studio
 
 - [Enhancement_Suite](https://github.com/marius-h/flutter_enhancement_suite) <!--stargazers:marius-h/flutter_enhancement_suite--> - Search for pub.dev libraries, update version, Bloc, Snippet, etc you're covered by [Marius Höfler](https://github.com/marius-h)