any
10-12 c.
13 cent.
13-16 c.
10-19th cent.
16 cent.
17 cent.
18 cent.
1812
18-19th cent.
19 cent.
18 cent. - 1917
1862
1868
1883
1900-1917
1901-14
19-20 cent.
1914-18
1918
1919
1921-1937
1918-40
1926-1932
1927-1935
1939- 45
1940-41
1941-45
1967
1945-90
1945 - 1999
20-21 cent
21cent
Igor Zakke (1926, Riga, Republic of Latvia – 2016, Riga, Republic of Latvia) – Doctor of Agricultural Sciences (Dr agr.).
Alexander Nikonov
Theodor Buchgoltz
Voldemar Knieriem
Gillel Segal
Viktor Timofeyev