A example of an expression or word mnemonic is

such as Pemdas - please excuse my dear aunt sally

Explanation:

A great example of an expression mnemonic that can help a student in an anatomy class to remember the names of the bones in the wrist is this one: Sally Left The Party To Take Cathy Home (Scaphoid, Lunate, Triquetrum, Pisiform, Trapezium, Trapezoid, Capitate, Hamate).

Another one that can help recall the names of the Great Lakes is this one:  Some Mice Hate Eating Onions  (Superior, Michigan, Huron, Erie, Ontario).  

other sources of text

explanation:

this can be magazines, news reports, scholarly articles, textbooks, research papers etc.

so they can differentiate themselves from others as they saw themselves as the superior race. the star was basically a symbol that meant you are a less of a person than i am because of my race. the star was also degrading for those who had to wear it because they were aware of this and the nazis used the notion to make them feel less like a person.