I am doing a study on nursing students satisfaction on the hospital attachment whether they are satisfied with the clinical attachment or not. I need more research studies on this
I am not sure what you mean by attachment in this context. Are you studying the student's satisfaction with their clinical placement? If so, classic attachment theory does not apply.
If you mean satisfaction with student clinical placements what you want to be including is the literature on issues nursing faculty have finding clinical placements, and the issues students have with these clinical placements, in order to establish the context of faculty decisions around the placements, and how the limitations of finding such placements affect student perceptions of their experience with the placement. This is important because the conditions and perceptions should be considered when examining any responses in satisfaction surveys and would influence the construction of the survey to include what has been identified as influencing placement in previous work. Much of that literature may be descriptive, or issue oriented rather than survey or other research based.
Next comes the literature of the research on your topic. If there are few if any studies specific to your focus on clinical placement, I would recommend diving into the literature on the validity and reliability of satisfaction surveys in general. Such surveys, while in wide use today, are notoriously unreliable, and can and often do lead to improper decisions without understanding what underlies the responses. You may have to go back many years (30 or more and work forward) to find the bulk of such studies, although studies in the past 10 years sometimes reference the earlier work.
Finally, you want to be sure to include an opportunity in the form of open-ended questions inviting the respondent to add any additional information or impressions specific to the focus of the survey as a whole, or at the end of each section of a survey for more specificity. The open-ended responses will be useful both for qualitative analysis of any themes or additional information not covered in the survey, and to check for inconsistencies with any scaled responses the respondent provided. Here is where satisfaction surveys find discrepancies between the ratings on the quantitative parts of the survey and can even find factors influencing these discrepancies. Past literature finds that people tend to rate items higher than they believe to be true. The open-ended part of the questionnaire might provide clues as to what the respondent believes independent of their ratings on the scales and may identify people who misread the scale so provided low ratings, while the open-ended question revealed high satisfaction, or vice versa. All of this will contribute to determining whether you were able to answer your research question and help in the construction of your Discussion section.