science-viewing-dev: 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/science-viewing-dev - from package: science-viewing-dev

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

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