Import multiple reference file field.

I have succesfuly imported multiple content fields before using the syntax in the documentation

title,body  
Title 1,values(Text 1+Text 2+Text 3)  

I have succesfuly imported single file

title;field_1;field_2
Title;values(903+904);sites/default/files/import/00006l.pdf

But when i try to import multiple files to multi value field the files are not imported.

title;field_1;field_2
Title;values(903+904);values(sites/default/files/import/00006l.pdf+sites/default/files/import/00006l.pdf)

The files are not imported is there such functionality in the module ?