faster output from php and postgres

Hi,
I am dealing with a database with many-to-many relation and have a php
script that joins these tables and displays the output.
But the problem is that after entering some 50 records the output is
very slow!
I can count till 50 before the script produces the output!
The complete description of the problem is written below..
Thanks in advance,
Mukta

description in detail:

database part:

Three tables: paper,author and author_paper

"A paper has many authors and an author has many papers."
In this way there is many to many relation.

The attributes of paper are: paper_id (primary key),title,journal,year
etc

The attributes of author are: author_id(primary key) and name

The attributes of author_paper are: author_id ,paper_id and level
( author with level=1 is the main author of the paper )

php part:

For an author:
1. get author_id from author table
2. select all paper_ids from author_paper table
3. For each of the above selected paper_ids:
a. print all the attributes of paper
b. select all authors of the paper and print their names in the
order
of their "level"