I was given this schematic and was asked to calculate the values of R1 , R2, R3 and C1 for frequency of 4Mhz. I looked through most of the electronics books such as The Art Of Electronics but was unable to find a circuit similar to this or any theory related to this type of crystal layout.If anyone has a clue pls let me know.

 

Perhaps the best way to evaluate this is to substitute X1 with the equivalent circuit fo X1.. I have not seen this particular circuit, but it should be quite easy to select ball-park values for the R's and C's after you have substituted X1, and then simulate to fine-tune these.