N. Wirth "Algorithms and Data Structures. Oberon version", 2004, updated 2012. 

The English version of the book (last update 2014-10-05, 2.3M):
AD2012.pdf

This version incorporates corrections and authorized modifications introduced in the Russian translation.

Program examples are available at http://zinnamturm.eu/downloadsAC.htm#ADen

The book is also available from N.Wirth's pages at ETH (a less recent version perhaps):
http://www.inf.ethz.ch/personal/wirth/books/AlgorithmE1/AD2012.pdf
(uncorrected original, 2004).

To read the sources and run the programs, one needs the BlackBox Component Builder (an Oberon derivative) freely available from http://www.oberon.ch/blackbox.html

BlackBox runs under MS Windows and Linux+Wine.

After installing BlackBox, unpack the above package into the BlackBox folder (so that ADen and i21sys subfolders appear along with Com, Comm, Ctl ... BlackBox.exe ...).

Run BlackBox.exe, open the file ADen/Docu/Sys-Map and read instructions.

The Russian page: link.

Enjoy!

Fyodor Tkachov
info21@inr.ac.ru