Litrum

Huic unitati sunt duo signa SI: littera Latina L, magnitudinibus parva (l) et magna (L).

• Chiliogramma
• Gallon
• Metrum cubicum
• Pint

• Bureau International des Poids et Mesures (2006). "The International System of Units (SI)" (PDF) 
• Bureau International des Poids et Mesures. 2006. "The International System of Units (SI)" (on-line browser):
  • Table 6 (Non-SI units accepted for use with the International System).
• National Institute of Standards and Technology (11 Novembris 2000). "Appendix C: General tables of units of measurement". NIST Handbook 44: Specifications, Tolerances, and Other Technical Requirements for Weighing and Measuring Devices. National Institute of Standards and Technology 
• National Institute of Standards and Technology. (December 2003). The NIST Reference on Constants, Units, and Uncertainty: International System of Units (SI) (web site):
• Taylor, B. N., et A. Thompson, eds. 2008a. The International System of Units (SI). United States version of the English text of the eighth edition (2006) of the International Bureau of Weights and Measures publication Le Système International d’ Unités (SI) (Special Publication 330). Gaithersburgi Terrae Mariae: National Institute of Standards and Technology.
• Taylor, B. N. and Thompson, A., eds. 2008b. Guide for the Use of the International System of Units. Special Publication 811. Gaithersburgi Terrae Mariae: National Institute of Standards and Technology.

• Turner, J. 2008. "Interpretation of the International System of Units (the Metric System of Measurement) for the United States". Federal Register 73(96): 28432-3.
• De litro apud situm bipm.org
• Unitates non SI inter civitates agnitae, apud situm aa.co.nz (UK National Physical Laboratory)
  • "Note on SI units," apud situm physics.nist.gov
  • "Recommending uppercase letter L," apud situm physics.nist.gov