bibtool: 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/bibtool - from package: bibtool

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

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