Hi vet2dong! Are you asking abot downloading from
www.vetelib.com? If yes, you have to click on the thank you button, where the downloadable material is posted, it will take you on a sharing site (depending where the document is placed by the uploader) and you must chose always the free, slower version. Sometimes you have to wait, skip ads, complete chaptas or so on, other times the download starts by itself. It happens sometimes that the file is no longer available, especially when you want to download from older posts. I hope this helped and i apologize for the late answer (I did not noticed the notification that you wrote me).
Best regards and feel free if you want to ask, I will try to help if I can.