@online{structtutorialspoint,
    title = {struct},
    date = {04-2020},
    url = {https://www.tutorialspoint.com/cprogramming/c_structures.htm},
}

@online{structchowto,
    title = {struct},
    date = {04-2020},
    url = {http://www.c-howto.de/tutorial/strukturierte-datentypen/strukturen/},
}