Historical clue formulations

• ___-Penh — 2013-02-28
• ___ Penh, Cambodia: Var. — 2009-07-08
• ___ Penh: Var. — 2007-03-06
• ___ Penh — 2006-05-21
• ___-Penh — 2004-03-18
• ___-Penh — 2002-11-16
• ___ Penh, Cambodia — 1998-12-29
• ____ Penh — 1995-10-19