diff --git a/app/controllers/personal_conferences_controller.rb b/app/controllers/personal_conferences_controller.rb
index 50536be..2043c41 100644
--- a/app/controllers/personal_conferences_controller.rb
+++ b/app/controllers/personal_conferences_controller.rb
@@ -40,7 +40,7 @@ class PersonalConferencesController < ApplicationController
       when "paper_types"
           writing_conferences_show = writing_conferences_temp.select {|value| search_all_words(value.conference_paper_types.collect{|x| x.title}.join(', ').to_s, params[:keywords])}
       when "period"
-          writing_conferences_show = writing_conferences_temp.select {|value| search_all_words(value.duration.include? params[:keywords]}
+          writing_conferences_show = writing_conferences_temp.select {|value| search_all_words(value.duration, params[:keywords])}
       when "publication_date"
           writing_conferences_show = writing_conferences_temp.select {|value| search_all_words(value.send("publication_date").strftime("%Y/%m").collect{|x| x.title}.join(', '), params[:keywords])}
       when "author_type"