• As early ( or As far back , or As long ago ) as 1925, 300 models of such engines had been or were being developed.
• This was accomplished back in 1770.
• As early ( or As far back , or As long ago ) as 1925, 300 models of such engines had been or were being developed.
• This was accomplished back in 1770.
Циммерман М., Веденеева К.. Русско-Английский научно-технический словарь переводчика. Russian-English scientific dictionary for translators. 2012