An Approach to a Simple Proof of Fermat’s Last Theorem (2018), latest update link
Note: Not finished yet.

An Elementary and Simple Proof of Fermat’s Last Theorem (2018)
Note: There is a mistake by using the method of equating the coefficients, so the proof failed.

On an alternative proof of Fermat’s Last Theorem (2014)

Über die diophantische Gleichung x³ + y³ = z³ (2014)

Über die Lösbarkeit der diophantischen Gleichung xⁿ + yⁿ = zⁿ (2014)