PbO ir amfotērais oksīds, bet uzdevumā ir uzrakstīts, ka tas ir bāzisks oksīds.
PbO amphoteric oxide: 1) Ullmann's Encyclopedia of Industrial Chemistry "Lead Compounds"
2) Lead Compounds. Kirk-Othmer Encyclopedia of Chemical Technology. (1999-2016). New York, NY: John Wiley & Sons. Online Posting Date: 18 Jun 2004
3) http://www.chemguideforcie.co.uk/section93/learningd.html
4) Periodicity, Quantitative Equilibrium and Functional Group Chemistry, p. 20