english: There is an interval of a tone between each of these, except between the third and fourth, and the seventh and eighth pitches which are a semi tone apart.
non_english: Â 1903:Â 20 Jan (ru);Â Â Â Â 17 Freb (ru);Â Â 18 Mar (ru);Â Â Â Â 21 Apr (ru);Â Â Â Â