phd1994: 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/phd1994 - from package: profphd-net

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

Error in other languages:
phd1994: bevel nie gevind nie
phd1994: comandă negăsită
phd1994: comando não encontrado
phd1994: commande introuvable
phd1994: command not found
phd1994: käsku ei ole
phd1994: không tìm thấy lệnh
phd1994: komanda nerasta
phd1994: Kommando nicht gefunden.
phd1994: kommandot finns inte
phd1994: komut yok
phd1994: nie znaleziono polecenia
phd1994: níor aimsíodh an t-ordú
phd1994: no se encontró la orden
phd1994: no s'ha trobat l'ordre
phd1994: opdracht niet gevonden
phd1994: parancs nem található
phd1994: perintah tidak ditemukan
phd1994: príkaz nenájdený
phd1994: příkaz nenalezen
phd1994: команда не найдена
phd1994: командата не е открита
phd1994: 命令找不到
phd1994: コマンドが見つかりません