<Tr> <Td> Ï </Td> <Td> ï </Td> </Tr> <Tr> <Td> Ḯ </Td> <Td> ḯ </Td> </Tr> <Tr> <Td> K̈ </Td> <Td> k̈ </Td> </Tr> <Tr> <Td> M̈ </Td> <Td> m̈ </Td> </Tr>

What are the two dots above a letter in german called