diff --git a/os/unix/admin/systemd/systemd-coredump.txt b/os/unix/admin/systemd/systemd-coredump.txt
index b7032c886..2fb67d201 100644
--- a/os/unix/admin/systemd/systemd-coredump.txt
+++ b/os/unix/admin/systemd/systemd-coredump.txt
@@ -37,6 +37,7 @@ man coredump.conf
 /run/systemd/coredump.conf.d/*.conf
 /usr/lib/systemd/coredump.conf.d/*.conf
 
+https://freedesktop.org/software/systemd/man/coredump.conf.html
 2021
 https://blogs.gnome.org/mcatanzaro/2021/09/18/creating-quality-backtraces-for-crash-reports/
     !!! need to read
diff --git a/pl/cross/methodologies/dp-patterns/refactoring-guru.txt b/pl/cross/methodologies/dp-patterns/refactoring-guru.txt
new file mode 100644
index 000000000..a476c0f29
--- /dev/null
+++ b/pl/cross/methodologies/dp-patterns/refactoring-guru.txt
@@ -0,0 +1,2 @@
+https://refactoring.guru/ru/design-patterns
+https://github.com/RefactoringGuru
diff --git a/pl/py/debug.txt b/pl/py/tools/quality/debug/debug.txt
similarity index 100%
rename from pl/py/debug.txt
rename to pl/py/tools/quality/debug/debug.txt
diff --git a/pl/py/tools/quality/debug/traceback/pystack.txt b/pl/py/tools/quality/debug/traceback/pystack.txt
new file mode 100644
index 000000000..91b5c281d
--- /dev/null
+++ b/pl/py/tools/quality/debug/traceback/pystack.txt
@@ -0,0 +1,10 @@
+https://bloomberg.github.io/pystack/overview.html
+https://pypi.org/project/pystack/
+https://realpython.com/python-traceback/
+
+qa
+https://stackoverflow.com/questions/1032813/dump-stacktraces-of-all-active-threads
+https://stackoverflow.com/questions/6849138/check-what-a-running-process-is-doing-print-stack-trace-of-an-uninstrumented-py
+https://stackoverflow.com/questions/132058/showing-the-stack-trace-from-a-running-python-application
+https://stackoverflow.com/questions/1156023/print-current-call-stack-from-a-method-in-code
+https://stackoverflow.com/questions/1781935/get-stacktrace-from-stuck-python-process-that-does-not-accept-signals