11.   There are many possible causes for elder abuse, which may be complex and involve several factors.

12.   Whatever other factors may be involved in these changes, plain terrorism is a major cause.

13.   Doctors have long suspected that some genetic factor was involved in the adverse reaction, which often occurs after patients have taken it for about two weeks.

14.   It would be impossible to determine if these birth defects were related to radiation exposure in the World War II generation or if other factors were involved.

15.   The AP excluded all accidents that did not clearly involve stalling engines, as well as cases that involved other factors, such as reckless driving.

16.   It was an incident which involves several factors.

17.   Stock market analysts in Mexico attributed the continued decline there to falling stocks on US exchanges but added that economic and political factors could be involved.

18.   Stock market analysts attributed the decline to falling stocks on American exchanges but added that other factors could be involved.