@book { InsomniaMedicalSleepDisorderDiagnosis,
    title = "Insomnia: Medical Sleep Disorder & Diagnosis",
    author = "Md Belal Bin  {Heyat}",
    year = "2016",
    publisher = "Anchor Academic Publishing",
    address = "Hamburg, Germany",
    url = "https://m.anchor-publishing.com/document/337729"
}