Wittgren, H. (1988). Removal of wastewater nitrogen in a wetland filter. Universitetet i Linköping.
Chicago Style (17th ed.) CitationWittgren, Hans-Bertil. Removal of Wastewater Nitrogen in a Wetland Filter. Linköping, Sweden: Universitetet i Linköping, 1988.
ציטוט MLAWittgren, Hans-Bertil. Removal of Wastewater Nitrogen in a Wetland Filter. Universitetet i Linköping, 1988.
אזהרה: ציטוטים אלה לעיתים לא מדויקים ב 100%.