Thanks for your response.
I tried another approach. Earlier I used Unity 4.2.2, now I've decided to change Unity to 4.3.4.
Currently, when I create Vuforia Unity project and I build it for the Android platform, it works. Furthermore, when I export Vuforia Unity project and later I import and run it in Eclipse, it works too.
I still have the problem, when I go through the article:
One section from that article, I have a doubt is
Copy the "/QCAR" folder (this should contain your Dataset .XML/.DAT files) from the "/raw" directory of the "QCARUnity" project to the "/assets" folder of the "QCARJava" project.
In subdirectory "/raw/QCAR" I have only one file named "unity.txt", that includes only word:
Is it expected?
Could someone give me any directions?