Merge pull request #67 from nromanen/yurembo

Yurembo
Merge pull request #68 from nromanen/yurembo

Validation Book. some changes. Bug fix
Merge pull request #69 from nromanen/master

Merge
Merge pull request #70 from nromanen/krivorotenko

Merge
Merge pull request #71 from nromanen/master

Merge