Der XXI. Abschitt.
Die Mechanik der festen Körper Theil 4, GDML_Books, (1769), p. 387 / Harvested from
Access to full text 
@article{PPN590259229+DMDLOG_0021,
     title = {Der XXI. Abschitt.},
     booktitle = {Die Mechanik der festen K\"orper Theil 4},
     series = {GDML\_Books},
     publisher = {R\"ose},
     address = {Greifswald},
     year = {1769},
     pages = {387},
     url = {http://dml.mathdoc.fr/item/PPN590259229+DMDLOG_0021}
}

 (éd.). Der XXI. Abschitt., dans Die Mechanik der festen Körper Theil 4, GDML_Books,  (1769), p. 387. http://gdmltest.u-ga.fr/item/PPN590259229+DMDLOG_0021/