orignla array:
Array
(
    [1] => data-analysis-essays
    [2] => research-questions-essays
    [3] => personal-information-essays
    [4] => financial-risk-essays
    [5] => customer-satisfaction-essays
    [6] => united-states-essays
    [7] => customer-loyalty-essays
    [8] => online-business-essays
    [9] => business-environment-essays
    [10] => american-airlines-essays
    [11] => airline-industry-essays
    [12] => research-design-essays
    [13] => consumer-perception-essays
    [14] => target-market-essays
    [15] => focus-groups-essays
    [16] => quantitative-research-essays
    [17] => information-technology-essays
    [18] => online-essays
    [19] => travel-essays
    [20] => quality-essays
    [21] => internet-essays
    [22] => companies-essays
    [23] => book-essays
    [24] => employees-essays
    [25] => reliability-essays
    [26] => china-essays
    [27] => process-essays
    [28] => marketing-essays
    [29] => personal-essays
    [30] => weather-essays
    [31] => framework-essays
    [32] => family-essays
    [33] => people-essays
    [34] => management-essays
    [35] => security-essays
    [36] => perception-essays
    [37] => description-essays
    [38] => journal-essays
    [39] => taxation-essays
    [40] => children-essays
    [41] => issues-essays
    [42] => entrepreneurship-essays
    [43] => history-essays
    [44] => europe-essays
    [45] => place-essays
    [46] => imagination-essays
    [47] => life-essays
    [48] => youth-essays
    [49] => amazon-essays
    [50] => behavior-essays
    [51] => london-essays
    [52] => australia-essays
    [53] => theory-essays
    [54] => space-essays
    [55] => wind-essays
    [56] => test-essays
    [57] => database-essays
    [58] => respect-essays
    [59] => privacy-essays
    [60] => branding-essays
    [61] => advertising-essays
    [62] => stability-essays
    [63] => microsoft-essays
)

remove array:
Array
(
    [1] => data-analysis-essays
    [2] => research-questions-essays
    [3] => personal-information-essays
    [4] => financial-risk-essays
    [5] => customer-satisfaction-essays
    [6] => united-states-essays
    [7] => customer-loyalty-essays
    [8] => online-business-essays
    [9] => business-environment-essays
    [10] => american-airlines-essays
    [11] => airline-industry-essays
    [12] => research-design-essays
    [13] => consumer-perception-essays
    [14] => target-market-essays
    [15] => focus-groups-essays
    [16] => quantitative-research-essays
    [17] => information-technology-essays
    [19] => travel-essays
    [21] => internet-essays
    [24] => employees-essays
    [25] => reliability-essays
    [26] => china-essays
    [28] => marketing-essays
    [29] => personal-essays
    [30] => weather-essays
    [31] => framework-essays
    [32] => family-essays
    [34] => management-essays
    [35] => security-essays
    [36] => perception-essays
    [37] => description-essays
    [38] => journal-essays
    [39] => taxation-essays
    [40] => children-essays
    [42] => entrepreneurship-essays
    [43] => history-essays
    [44] => europe-essays
    [45] => place-essays
    [46] => imagination-essays
    [48] => youth-essays
    [49] => amazon-essays
    [50] => behavior-essays
    [51] => london-essays
    [52] => australia-essays
    [53] => theory-essays
    [54] => space-essays
    [55] => wind-essays
    [57] => database-essays
    [58] => respect-essays
    [59] => privacy-essays
    [60] => branding-essays
    [61] => advertising-essays
    [62] => stability-essays
    [63] => microsoft-essays
)