pid type title authors mentors source_title published_date url doi isbn issn eissn kbcsm:400 "journal article" "Intermittent tramadol vs tramadol administration via patient-controlled pump after lumbar discectomy: a randomized controlled trial" "Kurtović, Biljana; Rotim, Krešimir; Sajko, Tomislav; Rotim, Cecilija; Friganović, Adriano; Milošević, Milan"