referencer: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/referencer - from package: referencer

You may install the required package with command apt-get install {package}

Error in other languages:
referencer: bevel nie gevind nie
referencer: comandă negăsită
referencer: comando não encontrado
referencer: commande introuvable
referencer: command not found
referencer: käsku ei ole
referencer: không tìm thấy lệnh
referencer: komanda nerasta
referencer: Kommando nicht gefunden.
referencer: kommandot finns inte
referencer: komut yok
referencer: nie znaleziono polecenia
referencer: níor aimsíodh an t-ordú
referencer: no se encontró la orden
referencer: no s'ha trobat l'ordre
referencer: opdracht niet gevonden
referencer: parancs nem található
referencer: perintah tidak ditemukan
referencer: príkaz nenájdený
referencer: příkaz nenalezen
referencer: команда не найдена
referencer: командата не е открита
referencer: 命令找不到
referencer: コマンドが見つかりません