Crystal Reports How do I show multiple items from 2 tables?

Message

                table_1a

table_1  <

           table_1b

Table 1 is connected to table 1a & 1b by a unique identifier.

I want to show all data where UID = whatever UID I choose from table 1.

1a might have 1 or 10 rows of data which display just fine. 

After the 10 rows of data from 1a I want to show the data from 1b which may have 1 or 5 rows of data.

If I put 1b in the footer, I only get 1.  If I put 1a in details a and 1b in details b, it doesn't report 1b accurately and it mixes them together.

How do I accomplish this?   Thank you in advance for any suggestions!

P.S. I tried a subreport which listed the 1b data 10 times and  if I chose suppress duplicate data, then I have a huge blank box on my report.