Much of the unpublished work was revised .
Much of the unpublished work was published by Wiechert , Gutenberg and Geiger , with his most important work that described the reflection and transmission of seismic waves in elastic media - the Zoeppritz equations - not being published until 1919 .
Much of the unpublished work was revised and published by Wiechert , Gutenberg and Geiger , with his most important work that described the reflection and transmission of seismic waves in elastic media - the Zoeppritz equations - not being published until 1919 .