The phrase "sufficient references" means that there are enough sources or pieces of evidence to support a claim, argument, or statement. Full definition
Great reproductions and the essay is enlightening with sufficient references, questions and suggestions to guide you through. (fadmagazine.com)
In the Pope's moving and thought provoking «Letter of Apology» to the Irish Church, issued shortly before the calls for his arrest, he mentions the fatal «tendency during this period to adopt ways of thinking and assessing secular realities without sufficient reference to the Gospel.» (faith.org.uk)
The Commissioner has determined that obtaining consent for a credit report falls into the «Sometimes Authorized» category, and recommends landlords «only require a credit check when a prospective tenant can not provide sufficient references about previous tenancies or satisfactory employment and income verification.» (landlordtalking.com)