DSO missing from command line - SFML

[Nielyboyken]

Hello

I'm using SFML to make a connection with a FTP-server; but for some reason it ain't working. I still do use approximately the same code as provided at SFML.
http://www.sfml-dev.org/tutorials/2.0/network-ftp.php

My C++ code:

#include <iostream>
#include <SFML/Network.hpp>

using namespace std;
int main() {
sf::Ftp ftp;
ftp.connect("ftp://myWebsite.com", 21, sf::seconds(120));
ftp.login("myUsername", "myPassword");
}

Like you see, I'm not even started on my project.

G++ Compiler input:

g++ -o app app.cpp -lsfml-network

G++ Compiler output:

/usr/bin/ld: /tmp/ccjQFzpo.o: undefined reference to symbol '_ZN2sf7secondsEf'
//usr/lib/x86_64-linux-gnu/libsfml-system.so.2: error adding symbols: DSO missing from command line
collect2: error: ld returned 1 exit status

Normally, SFML is installed correctly because this example is running well on my PC:
http://www.sfml-dev.org/tutorials/2.0/start-linux.php

Some specifications that might help:
OS: Linux Mint 17 => Cinnamon
Editor: Vim
Compiler: G++
Library: SFML (Network.hpp)

Already tried to searching for answers, but only answers were that I needed to add something to my flags or makefile. But I ain't on a ship nor having a makefile in my 'project'.

I added -lpthread to my G++ command once, and then the first line of the error disappeared.. But the DSO etc, stays.

Anyone able to help?

Thanks for reading,
Niely

[norm b]

//usr/lib/x86_64-linux-gnu/libsfml-system.so.2: error adding symbols: DSO missing from command line

Pretty good hint in that line. DSO = Dynamic Shared Object

[Nielyboyken]

Yeah, I already found that in my research. But what is it, what does it mean, how to add it then, and more important, how to fix it.

[Nielyboyken]

Ah, I just had to ad -lsfm-system to my G++ command? :)
Thanks for the help (if that's indeed it).