a small number contain vs a small number contains

Some examples from the web:

• The common position contains only a few new features and makes only a small number of changes, principally of wording.
• -< Invented name > contains polyoxyethylene hydrogenated castor oil that may, in a small number
• Because this instrument is a sectoral one: it contains a small number of provisions on data protection which are specific to criminal records and therefore they are more restrictive.
• However, Directive 94/25/EC contains a small number of provisions which apply or could be deemed as applying to private importers as regards performing the conformity assessment (post-construction assessment).
• Haematuria/ proteinuria occurred in a small number of patients.
• A small number of girls were pulled from the main group.
• Children Leukaemia has been reported in a small number of children treated with somatropin.
• A small number (total of 98) of Caucasian patients were treated with telbivudine.
• Most aminotransferase abnormalities were transient; however, a small number of patients experienced more prolonged elevations.
• Only a small number of patients have received systemic chemotherapy and IT ziconotide.
• Only a small number of patients have received systemic chemotherapy and IT ziconotide.
• There have been a small number of post-marketing case reports of intentional overdose with anagrelide.
• Aggression may occur in a small number of patients who have received antidepressants, including venlafaxine.
• Contained within this vacuum chamber are a small number of atoms.
• There is a small number of infected premises for which no clear origin has yet been established.
• There are a small number of areas where you rapporteur proposes amendments.
• A small number of amendments have been made to clarify various aspects of the Proposal.
• The new regulation is expected to remove only a small number of further substances from use, namely the worst remaining ones.
• The US authorities had admitted that a small number of renditions had taken place immediately after 9-11.
• There may have been a small number of humans.

Some examples from the web:

• The common position contains only a few new features and makes only a small number of changes, principally of wording.
• -< Invented name > contains polyoxyethylene hydrogenated castor oil that may, in a small number
• Because this instrument is a sectoral one: it contains a small number of provisions on data protection which are specific to criminal records and therefore they are more restrictive.
• However, Directive 94/25/EC contains a small number of provisions which apply or could be deemed as applying to private importers as regards performing the conformity assessment (post-construction assessment).
• Haematuria/ proteinuria occurred in a small number of patients.
• A small number of girls were pulled from the main group.
• Children Leukaemia has been reported in a small number of children treated with somatropin.
• A small number (total of 98) of Caucasian patients were treated with telbivudine.
• Most aminotransferase abnormalities were transient; however, a small number of patients experienced more prolonged elevations.
• Only a small number of patients have received systemic chemotherapy and IT ziconotide.
• Only a small number of patients have received systemic chemotherapy and IT ziconotide.
• There have been a small number of post-marketing case reports of intentional overdose with anagrelide.
• Aggression may occur in a small number of patients who have received antidepressants, including venlafaxine.
• Contained within this vacuum chamber are a small number of atoms.
• There is a small number of infected premises for which no clear origin has yet been established.
• There are a small number of areas where you rapporteur proposes amendments.
• A small number of amendments have been made to clarify various aspects of the Proposal.
• The new regulation is expected to remove only a small number of further substances from use, namely the worst remaining ones.
• The US authorities had admitted that a small number of renditions had taken place immediately after 9-11.
• There may have been a small number of humans.