refdbib: 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/refdbib - from package: refdb-clients

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

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