Uppercase/lowercase paper titles on a CV
Formatting of titles in citations is specified by citation style guides, APA, for example and depends on the context. If you are formatting your CV in APA style, you would use the link I provided and use "sentence case" for both titles (capitalize first word only) in your CV.

Note that this does not depend on the capitalization of the title in the original source; you should consider the title capitalization to be a formatting issue which will vary across formatting schemes but should be standardized when you bring the works together, like in a references list or CV.

This goes for English capitalization rules; I am not aware of APA guidelines for citations in other languages, such as German, which use different capitalization. Without further guidance, I would just suggest to be consistent.