German Resource's.

[undead reindeer cavalry]

Lots of arguments in this post, though very little information.Zetterling has only two books that focus on east front. Is that it for well researched work on east front operations from the german perspective?

there are probably more books than you ever find time reading or money buying.

there's no single name like Glantz is for Soviets. if you want army group level stuff, look for example the series by Haupt. if you want army level stuff, look for example "Drama between Budabest and Vienna" by Maier. if you want accounts on single operations look for example Kurowski's "Bridgehead Kurlans" or Nipe's "Last Victory in Russia" or "Decision in Ukraine". if you want division level stuff there's quite a number of unit histories for various German units. if you want a single book about East Front from German perspective, that has "enough" depth for you, i'd start with "Germany in World War 2, Vol IV". don't hurt your back when you pick it up the first time.