This series by Kostrov and Beliavsky is also available on Scribd in multiple volumes, including Volume 2 and Volume 3 .
A preview of the first volume including tactical hints for various positions is available at De Beste Zet . Download Chess Tactics Exercises Vol pdf
This volume contains 1,343 exercises grouped by combinational methods and is hosted on the Internet Archive . This series by Kostrov and Beliavsky is also