diff --git a/cards/learning.org b/cards/learning.org
new file mode 100644
index 0000000..ddc88d2
--- /dev/null
+++ b/cards/learning.org
@@ -0,0 +1,53 @@
+:PROPERTIES:
+:ID:       093b340a-3f5e-4a46-9017-f74b89caab13
+:END:
+#+title: Anki: Learning process
+#+date: "2021-05-12 13:09:27 +08:00"
+#+date_modified: "2021-05-12 13:30:08 +08:00"
+#+language: en
+#+property: anki_deck Learning process
+
+The cards here are based from the course titled "Learning how to learn" taught by Barbara Oakley and Terence Sejnowski.
+
+
+
+
+* Pitfalls and illusions of competence
+:PROPERTIES:
+:ANKI_DECK: Learning process
+:ANKI_NOTE_TYPE: Styled cards
+:END:
+** Front
+Give various pitfalls and illusions of competence to look out when learning.
+** Back
+- *The presence of the material itself* can cause students to foolishly think they already know about the subject.
+- Similarly, *studying with solutions can be a trap if you focus on the what and how rather than the why*.
+- Various common practices such as highlighting, rereading, and mind mapping are not as effective and only applicable in specific situations.
+- The einstellung mindset, *being invested in an idea that you can't see other solutions*.
+- Similarly, *overlearning can occur if you're aiming for complete mastery when you should move on after understanding the concept*.
+
+* Practices for studying
+:PROPERTIES:
+:ANKI_NOTE_TYPE: Styled cards
+:END:
+** Front
+Give various practices for studying effectively.
+** Back
+:PROPERTIES:
+:ID:       85cd8ec5-c96c-496f-a748-5dd9d2c1136d
+:END:
+- *Recalling is one of the more effective practices compared to rereading or highlighting.*
+  Self-testing is one of the better strategies, overall.
+
+- *Prefer spaced repetition* over cramming as scientifically, the learning process takes some time to settle.
+
+- *Get the key ideas ahead* and as you're studying, fill the details.
+  This includes skimming — reading through the chapter, looking at the keywords.
+
+- *Practice interleaving your studies* — that is, studying other subjects and/or moving to later topics as you understand the topic.
+
+- *Focus, understand, and practice.*
+  Learning can occur bottom-up (learning the details of a problem) and top-down (learning the bigger picture of a topic).
+  Using both creates context and that's where you put your understanding to the test as you learn when to apply what you've learn.
+
+- Use memory palace technique — that is, to *create analogies, narratives, and mnemonics*.
diff --git a/cards/linux.org b/cards/linux.org
index 01be193..f335f06 100644
--- a/cards/linux.org
+++ b/cards/linux.org
@@ -3,7 +3,7 @@
 :END:
 #+title: Anki: Linux
 #+date: "2021-05-01 20:20:25 +08:00"
-#+date_modified: "2021-05-08 11:15:50 +08:00"
+#+date_modified: "2021-05-12 14:28:29 +08:00"
 #+language: en
 #+property: anki_deck Linux
 
@@ -103,3 +103,71 @@ Only select packages available as a runtime (e.g., Qt, GTK).
 Flatpak has its set of runtimes composed of system libraries to be used with the applications.
 Thus, it stays out of its way with the operating system's libraries.
 The developer can also bundle its own set of libraries.
+
+* Changing user shell
+:PROPERTIES:
+:ANKI_NOTE_TYPE: Styled cards
+:ANKI_NOTE_ID: 1620793135173
+:END:
+** Front
+How to change user shell in most Linux distros?
+** Back
+~chsh~
+
+* Printing a list
+:PROPERTIES:
+:ANKI_NOTE_TYPE: Styled cards
+:ANKI_NOTE_ID: 1620793135476
+:END:
+** Front
+Give some ways to print a list.
+** Back
+#+begin_src shell
+# Format the string.
+printf "%s\n" foo bar 'baz ;;'
+
+# Echo the string as-is.
+echo "foo
+bar
+baz ;;"
+
+# Print with escaped newlines.
+echo -e "foo\nbar\nbaz ;;"
+#+end_src
+
+#+results:
+: foo
+: bar
+: baz ;;
+: foo
+: bar
+: baz ;;
+: foo
+: bar
+: baz ;;
+
+* systemd timestamp example
+:PROPERTIES:
+:ANKI_NOTE_TYPE: Styled cards
+:ANKI_NOTE_ID: 1620793135853
+:END:
+** Front
+What is ~*-*-8/4~ in systemd calendar format?
+** Back
+:PROPERTIES:
+:ID:       a118fdec-8026-433b-9a58-b738183be7a2
+:END:
+Every 4 days, starting from the 8th of the month.
+
+Assuming this was executed on 2021-05-12.
+
+#+begin_src shell
+systemd-analyze calendar *-*-8/4
+#+end_src
+
+#+results:
+:   Original form: *-*-8/4
+: Normalized form: *-*-08/4 00:00:00
+:     Next elapse: Sun 2021-05-16 00:00:00 PST
+:        (in UTC): Sat 2021-05-15 16:00:00 UTC
+:        From now: 3 days left
diff --git a/cards/org-mode.org b/cards/org-mode.org
index 212bec0..8677cca 100644
--- a/cards/org-mode.org
+++ b/cards/org-mode.org
@@ -4,7 +4,7 @@
 :END:
 #+title: Anki: Org mode
 #+date: "2021-05-05 22:49:10 +08:00"
-#+date_modified: "2021-05-10 08:39:52 +08:00"
+#+date_modified: "2021-05-12 11:07:56 +08:00"
 #+language: en
 
 * org-babel
@@ -172,8 +172,6 @@ Give some ways how to navigate Org mode documents quickly.
 
 - ~org-backward-heading-same-level~ is the same as ~org-forward-heading-same-level~ but moves one headline backwards.
 
-- ~org-edit-special~ creates a buffer for certain elements in org-mode but it is especially useful for editing source code blocks where it will open with the correct major mode.
-
 - ~org-forward-heading-same-level~ moves one headline forward in the same level.
   Useful for navigating sections and subsections.
 
@@ -185,3 +183,12 @@ Give some ways how to navigate Org mode documents quickly.
 
 - ~org-sort~ will sort the entries into your preferred criteria.
   It also works on a list of items which is very useful if one of the list items has more than one line.
+
+* Editing source code blocks
+:PROPERTIES:
+:ANKI_NOTE_TYPE: Styled cards
+:END:
+** Front
+What function creates a buffer for certain elements in org-mode but it is especially useful for editing source code blocks where it will open with the correct major mode?
+** Back
+~org-edit-special~