Submit a pdf or ps file electronically. Alternatively, send an e-mail to one of the managing editors or to [email protected] with a web address (e.g. a math-arXive address) where we can find a ps file or pdf file of your paper. Sending a (La)TeX version by mail is also possible, but is less preferable as it may lead to (teXnical) problems; please add the address of the corresponding author.