While comiling java for RTC, many classes like "com.ibm.team.links.common.IReference" are missing, where are they?

Hello,
I'm using RTC 6.0.2

I would like to download / upload Work Items attachments based on the information found there:  
https://rsjazz.wordpress.com/2012/09/21/downloading-attachments-from-work-items/
https://rsjazz.wordpress.com/2012/08/01/uploading-attachments-to-work-items/

I started with the download side and try to compile the
WorkItemDownloadAttachment.java with javac.

There are many "import class" which I don't have.
I did not see them in the RTC-SDK, nor in the Eclipse RTC environment. May I didn't look weel.

The necessary classes are:
import com.ibm.team.links.common.IReference;
import com.ibm.team.process.client.IProcessClientService;
import com.ibm.team.process.common.IProjectArea;
import com.ibm.team.repository.client.ITeamRepository;
import com.ibm.team.repository.client.ITeamRepository.ILoginHandler;
import com.ibm.team.repository.client.ITeamRepository.ILoginHandler.ILoginInfo;
import com.ibm.team.repository.client.TeamPlatform;
import com.ibm.team.repository.common.TeamRepositoryException;
import com.ibm.team.workitem.client.IAuditableClient;
import com.ibm.team.workitem.client.IWorkItemClient;
import com.ibm.team.workitem.common.IWorkItemCommon;
import com.ibm.team.workitem.common.model.IAttachment;
import com.ibm.team.workitem.common.model.IAttachmentHandle;
import com.ibm.team.workitem.common.model.IWorkItem;
import com.ibm.team.workitem.common.model.IWorkItemReferences;
import com.ibm.team.workitem.common.model.WorkItemEndPoints;