pbibtex: 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/pbibtex - from package: texlive-binaries

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

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