Sokoban 30th anniversary 1982-2012 (Continuation)

One of the most outstanding puzzles in the "Original" collection is the level 20. In fact, this is the first level that presents difficulties of some importance to the beginner player. Here I have collected 14 variations of this level, all that I know.

1.
Author: unknown (Thinking Rabbit)
Game: 倉庫番2 (Sokoban 2)
Title: Level 10
Developer: Thinking Rabbit
Publisher: Thinking Rabbit (Japan)
Platform: NEC PC-8801mk2, NEC PC-8001mk2, NEC PC-9801, FM-7, NEC PC-6001mk2, IBM JX, NEC PC-9801m2
Released: February 1984

2.
Author: unknown (Thinking Rabbit)
Game: Soko-Ban
Title: Level 20
Developer: Thinking Rabbit, ASCII Corp. (Japan)
Publisher: Spectrum HoloByte, Inc. (USA)
Platform: Apple II, DOS, Commodore 64, TRS-80 Color Computer
Released: 1988 

3.
Author: Tommy in Pennsylvania
Collection: MacTommy inventions
Title: Level 20
Comment:
This collection was included first in the freeware MacSokoban, by Ingemar Ragnemalm, for Macintosh; and later in KSokoban (v0.1.0, August 1998), by Anders Widell, for KDE platforms.
Date: January 1996

4.
Author: Kurt Nittel
Set: SokoNittel 1
Title: Level 20
Date: 1998

5.
Author: Thomas Jensen
Game: WSokoban! 2.0
Title: Level 13
Publisher: Thomas Jensen (Denmark)
Platform: Windows 9x/NT
Released: July 1998

6.
Author: Howard Abed
Collection: Fourth Set
Title: Level 10
Date: June 1999

7.
Author: Howard Abed
Set: Simple levels
Title: Original 9
Comment - H.A.: Remodel of original level 20
Date: March 2001

8.
Author: Frédéric Maire
Game: Pousseur
Title: Level 11
Comment: The original level is wrong: missing two goals.
Platform: Javascript
Website: www.interjeux.net/jeux/pousseur/index_fr.html
Date: May 2000

9.
Author: unknown (Thinking Rabbit) + York Shen
Title: Sokoban Perfect 226 a
Comment - Y.S.: One wall moved in entrance to collections area.
Date: July 2003 (?)

10.
Author: Eric F. Tchong
Collection: Aruba 8
Title: Level 9 Memories
Date: September 2004

11.
Author: Jordi Doménech
Collection: Original remixed
Title: Level 20
Date: July 2009

12.
Author: unknown (Thinking Rabbit) + Jordi Doménech + anian
Title: MF8 7th Sokoban Competition
Comment: Based on Original remixed #20 by Jordi Doménech, remodel of Original #20 from Thinking Rabbit.
Date: September 30, 2009
URL: bbs.mf8-china.com/forum.php?mod=viewthread&tid=39854&extra=page%3D2

13.
Author: unknown (Thinking Rabbit) + Jordi Doménech + anian + Tian Lang
Title: MF8 7th Sokoban Competition
Comment:
增加两只箱子，拼个“七” - T.L.
The goals in the central area are the Chinese number "7" (七) - J.D.
Date: October 25, 2009
URL: bbs.mf8-china.com/forum.php?mod=viewthread&tid=41064&extra=page%3D3

14.
Author: Eric F. Tchong
Collection: Chuchubi 14
Title: Level 46 Old timer
Date: july 2011