The last update to Form N-400, Application for Naturalization, was September 17, 2019. U.S. Citizenship and Immigration Services (USCIS) only accepts the current version of the form.
Also available here are translations of the N-400 by community-based partner organizations. There is also video translation of the 2/4/14 N-400 into Khmer available, courtesy of The Cambodian Family (www.cambodianfamily.org).
A step by step guide to completing the N-400 is available here.