Bulgarian inventions (What the world does not know)

This is a list of Bulgarian inventions. I am sure that is not all of it but those are the most famous ones: 

• John Atanasoff - invented the prototype of the first electronic calculation machine used for the creating of the modern computer.

• Ivan Mitev - discovered the sixth tone in the heart.

• Georgi Nadjakov - discovered the photoelectret state essential to modern photocopying.

• Ivan (John) Notchev - constructed the engines for the lunar module used during the first landing on the Moon.

• Dimitar Paskov - created the medicine Nivalin. (that is a muscle relaxant)

• Petar Petrov - invented the prototype of the digital electronic watch.

• Dimitar Sasselov - In 2003 the Bulgarian astronomer and his team discover the most distant planet. It is 5000 light years away from the Sun. It`s located in the constellation of the Sagittarius and is called OGLE-TR-56b.

• Asen Yordanov - He constructed the first Bulgarian aeroplane. He is also one of the creators of the airbag.

• Roumen Antonov - invented a revolutionary continuously variable transmission.

• Stamen Grigorov - discovered the true cause for the existence of natural yogurt - Lactobacillus bulgaricus. He also made a major contribution to the creation of an anti-tuberculosis vaccine.

The Bulgar calendar was a calendar system used by the old Bulgarians to measure the duration of the year. It was acknowledged by UNESCO as the most accurate ancient calendar.